Apple's appropriation of Launchbar's default key combo is no accident. Spotlight, in practice, works the same way as Lanuchbar. Its menu even pops out of the same corner of the screen. Spotlight can be used as an everyday tool to launch applications, bring up sites in your bookmarks, play iTunes songs, etc. But because Spotlight is more ambitious than Launchbar, it's quite a bit slower, because it's pulling up a lot more stuff when you search for P-H-O. You can customize Spotlight so it only indexes a few types of items, thus making it work more like Launchbar or Quicksilver, but that makes it less useful for what it's really good for. I ended up changing the key combo of Spotlight, and keeping Quicksilver set to the old command-space key combo that I originally became accustomed to with Launchbar.
So Apple's up to its old tricks again, systematically cribbing the cool ideas from essential shareware apps and integrating them into the OS, just as it did with Watson/Sherlock. But just as Sherlock was enough like Watson to kill it off but not enough like it to be a complete replacement, Spotlight is too feature-rich to replace Launchbar or Quicksilver for me.
On the subject of Apple ripping off ideas for shareware apps, one of Apple's most visible new features is Dashboard, which is nifty, but mostly for eye candy purposes. The push of a button superimposes several handy "widgets" over the desktop: a cute clock, a calendar, a nice weather forecast, and a calculator, with the ability to activate and download others. The coolest part is when you add a new one, it's "dropped" onto the screen with a ripple like water. Wow! It's beautifully conceived, and should prove to be handy.
It's also a blatant rip-off of Konfabulator, a shareware app. But Konfabulator costs money, and Dashboard is better-integrated and even more beautiful. So while Apple's appropriation of ideas from the shareware sphere might be bad news for those developers, overall it's a big plus for Mac users. And while I'm personally sympathetic for their plight, I don't fault Apple for doing it. They have to get cool new features from somewhere. Heaven knows that once one person has thought up something cool to do with software, eventually everyone else will copy it. It's a logical progression: Mac Shareware authors --> Apple --> Microsoft --> Linux. (Just kidding, everyone!) But if we were to try to prevent it, we'd be shooting ourselves in the foot by stifling innovation. So, sorry Launchbar and Konfabulator developers. Imitation is the best form of flattery, and your ideas were really cool. Just hope that Apple never gets around to completely replicating your functionality.
On the subject of eye candy, Tiger sports a refined user interface, with somewhat flattened and softened features. I still hate the brushed metal, and it's still used all over the place for no good reason, but overall the subtle UI changes make Tiger look different enough to be distinctive, and a little better looking, in my subjective opinion.