Things that Apple won't change, or will resist changing for far too long
One of the most tantalizing potential features of the iPhone is using its built-in wi-fi to make and receive calls using Voice-over-IP. This could be done in concert with the carrier such as with the new VoIP crossover service that T-Mobile recently launched in the US. Or it could be designed to totally bypass the carrier, using VoIP over wi-fi as a primary, and failing over to cellular if wi-fi isn't available. Current VoIP services like Vonage and ViaTalk already allow a VoIP call to be forwarded to a cell phone if the network is down. Apple could set up a VoIP service, hand out phone numbers, allow iPhone and home phones to be used interchangeably, and provide a forwarding service to an AT&T cell phone number that's only used for forwarding.
If and when the iPhone platform becomes more open to custom applications, a system like this could easily be created without Apple's involvement, and Vonage and other VoIP providers could set up iPhone plans that integrate with their current offerings. Apple, of course, could (and probably will) try to keep this from happening. If they were really smart (and if they could do it without getting sued by AT&T, who would certainly be furious), they would set up their own service, and relegate the carrier to fail-over status, and eventually with Wi-Max or a similar new technology, bump out the carriers altogether and build out their own network (or partner with Google, who already has plans to do something like this).
Apple will resist offering an officially unlocked phone for far too long. How do I know this? Because Apple has an exclusive contract with AT&T for five years. It will not be able to offer an unlocked phone in any part of the world for at least that long. And that's too long. I suspect that Apple will be using the iPhone's cachet to negotiate extremely favorable deals with carriers that give a kickback of usage fees to Apple, so they'll be loath to allow anyone with a prepaid SIM to use the iPhone. It's possible that the only thing that would get Apple to unlock the iPhone would be government legislation. Keeping phones locked will probably always be legal in the US, but other countries already explicitly allow phone unlocking, and even mandate it.
The lack of any kind of file management in the iPhone is a serious headache for those of us trying to use it for serious work. Apple wants to win the business market, so some kind of file management and document editing will certainly be in the pipe. But I suspect that Apple will try to keep a pretty tight lid on the files you install on the iPhone. Why? iTunes. Apple wants to make money, and they know that they will be able to make money by selling stuff for the iPhone using the iTunes store. They'll want to sell you music, of course, but also ringtones, applications, wallpapers, games, ebooks, etc (see the next section for more on this). So I think that while Apple will be forced to allow for some file management, they may try to make it difficult to easily transfer and manage any type of file, and will probably not make it easy to convert any mp3 into a ringtone, transfer free ringtones you downloaded online onto your iPhone, download mp3s directly on the iPhone from non-iTunes sites and load them into the iPhone's iPod, and, of course, send songs, ringtones and videos from one iPhone to another over wi-fi. These are killer features that all iPhone users would want, but I fear that Apple will not implement them in order to protect potential revenue streams and placate the entertainment industry.
This fourth section of my article was the hardest one to write, because I'm blinded by my own hope. I want Apple to implement all of my ideas and suggestions. I don't want to have anything in this section, because there are features in this section that I desperately want for my own iPhone. Our only hope of getting these features is either that Apple will reverse course and open up the iPhone's platform as much as the Mac is open to outside development and third-party developers can deeply customize the device, or that the many hackers trying to pry the iPhone open will succeed, and Apple will be unable to put the genie back into the bottle with subsequent updates.
The last feature that I'm putting into section three is the one that I most desperately wanted to put into section one. It's about Bluetooth. Like many mobile phones, Apple shipped the iPhone with a severely crippled Bluetooth spec. Bluetooth on the iPhone can be used only for connecting a headset. The iPhone's Bluetooth can not be used to exchange files with another device, sync with a Mac wirelessly using iSync (like many other non-Apple phones can), allow for a wireless serial connection, such as tethering, or any of the other useful things that a complete Bluetooth implementation will allow.
The inability of the iPhone to use Apple's own iSync is a total disgrace. It must be connected to your computer via USB, and all syncing is done through iTunes. Getting files onto the iPhone is very controlled, and the necessity of keeping everything managed through iTunes can make things very difficult when you want to connect your iPhone to multiple computers. The most nerve-wracking thing of all for me, though, is that since the battery can't be replaced, and you only get about 400 charges out of the battery, you really shouldn't be constantly plugging and un-plugging your iPhone from power, as it shortens your battery life. But if I want to put a file on the iPhone, I only have two choices: email it to myself (and have it live forever attached to the email and otherwise inaccessible) or plug in and sync with iTunes, which only works with a few types of files and affects my battery life each time unless I restrict file transfers to nightly charging sessions.
The iPhone's lack of wireless sync also makes its calendar and address book that much less useful, and squanders an opportunity for the mail application to be much more useful. Wouldn't it be so much more cool if the iPhone were constantly reconciling the emails you send and receive on your iPhone with those on your desktop computer, whenever your network allowed it?
The Mac also has a built-in utility called Bluetooth File Exchange. It doesn't work with the iPhone. Of course, you also can't use Bluetooth to exchange files between iPhones, or conduct private IM chats, receive notifications that your friends are within Bluetooth range, or all the other cool tricks that would be possible with a wide-open Bluetooth implementation.
One of the neatest Bluetooth tricks that you can do on the Mac is possible with an app called Salling Clicker. Salling Clicker makes your Mac aware of your presence when you're within Bluetooth range. You can have it set up scripts to do certain things depending on your proximity and status. You could have it put your Mac to sleep when you walk away, mute iTunes on your Mac when you get a phone call, or display caller-ID on your Mac's screen. It was originally developed merely as a remote control utility. You could use your cell phone as a "clicker" to control your Mac, like to advance slides in PowerPoint, or switch songs in iTunes or pause the movie from across the room. If you could develop a full-featured app on the iPhone that integrated with Salling Clicker on your Mac, you could do some really cool stuff. The kind of stuff that would merit its own Steve Jobs keynote.
But I fear that it won't happen. And the most frustrating thing about my decision to put the iPhone's broken Bluetooth implementation into section four is that, unlike the other items in here, I just can't wrap my head around Apple's reasons for doing it this way. Typically, carriers want to cripple phones' Bluetooth implementations because they want to force you to buy ringtones and apps through them, and Bluetooth makes it a little too easy to circumvent that, or they want to draw an artificial line between their cheaper, consumer-level phones and their more full-featured, professional phones (that cost more). Apple only has the one phone, and it's expensive and targeted at the top of the market, so that second justification doesn't apply. But I've already postulated that Apple's setting the stage for a lucrative iTunes-based media and add-on market, but it just doesn't make sense that Apple would forego so much cool capability for only that reason.
And it's because I can't figure out why Apple crippled Bluetooth, that I'm going to assume they have a totally insane reason that makes perfectly good sense to them, that they did it with total clarity of purpose, and that they won't fix it any time soon.