Apple should let you sync all the iTunes libraries on your network into one, stored on your Time Capsule.

What I would like to see is a firmware update for Time Capsule that lets you synchronize all the iTunes libraries on your network into one giant library on your Time Capsule.

This would let you do a couple of things, firstly, if Apple made a cheap version of Apple TV that didn't have a hard drive in it, you could stream any of your media from the iTunes library on the Time Capsule at any time, as your Time Capsule is always on.

Also, if you are a MobileMe subscriber, you would be able to use a 'Back To My Mac' style service to remotely watch and listen to your iTunes content over the Internet, either on another Mac or iPhone/iPod Touch.