I recommend that OS vendors take into account the huge organizational need that have arisen from the massive adoption of digital music and photography and make it a priority to provide tools that aid in the organization of those materials and try to make sure that the specialized application vendors have access to the programming interfaces to these tools so their solutions can be synchronized. Apple and Microsoft have both developed their own music and photo management software. As good or bad as they are, they're currently a level of abstraction away from the management of the actual media files themselves. That's neither intuitive nor convenient for anyone. In the long run, the more file navigation becomes turned on to the unique attributes of the particular types of files, the better things will be.
Ever since multitasking came on the scene, computer users have struggled with how to deal with switching between multiple process and working documents. The Macintosh Finder, Windows taskbar, Unix virtual workspaces, and recently Apple's Exposť have gradually made that task a bit easier, but it's still a vital issue. Novices struggle with the basic concepts at first, but power users tend to suffer the most, as they tend to have more things going on at once. Mouse-based interfaces can lead to a lot of hunting and clicking when you've got a zillion windows open. There just hasn't been much innovation on this front in many years.
Now that I've tried to make the case for computers being less intuitive, let's talk about how they desperately need to be easier to use. The personal computer is by far the most unreliable piece of equipment in the modern household or workplace. Other machines, such as automobiles, may be more complicated and difficult to service, but we have become accustomed to a certain danger of catastrophic failure from our computers that we do not face from any other machine. Sure, the circular saw may cut your hand off, but you can pretty much guarantee that it was your own damn fault and you'll understand exactly what went wrong as soon as you get the blood flow stopped. Only the family lawnmower can usually come close to the finickiness of the average family computer.