A decent camera, so I can throw away my current camera. It would be nice to be able to organize pictures/movies on the device you make them with. With a Pandora you could not only do that, but also use Gimp or whatever software, connect it directly to a beamer or TV, or share them via a webserver, bluetooth, usb etc. Obviously there's no room for a real good camera, but a decent 10 megapixel camera with the ability to record HD movies should be possible.
Nubs with little sticks on them, that can be pushed in like little telescopic thingies if you want to close the lid, and you just have to press them to make them come out again. I have no clue if something like that exists, but it would be cool. Something like the clicker thingie on a ballpoint pen would do.
Three full SD slots and four microSD slots. The microSD slots could all be hidden behind the battery, and could be used to make your own tiny SSD by putting in 4 identical cards and use them in RAID5. Or you could do pretty much anything else with them (e.g. two in RAID0 for unimportant data and two in RAID1 for important data, or just four independent cards). The three full SD slots would be useful in case you want to copy card A to card B while you still want to use data or applications from card C.