On my next camera, I'd like the timestamps to have better resolution than the burst rate. It's confusing when the pics aren't strictly ordered by time (although that could be a limitation of the software I'm using).
I'd also like a built in GPS for time sync and geo-tagging, preferably one smart enough to know what's up with daylight savings at its current location (although post processing would be ok there).
Furthermore, it'd be cool if it could be flash-triggered so you could take a sync shot with another camera and have this one take a shot also, so you can compare images later and calibrate out any clock offset.