Here is what I think is missing:
Bluetooth for getting images from your phone or sending to others (phones or iPods)
A mechanism for downloading photos from your camera
QuickTime Capture (from an external camera via Firewire or USB), QuickTime Playback and anything else related to QuickTime.
(How fast can it change between images, can video be simulated?)
Wouldn’t it be nice to plug in your iSight and record a video…