My main features would be:
- Good touchscreen with minimal glare.
- Fully working wifi so I can access bookstores and my home network.
- User replaceable battery.
- Memory slots.
- Access to bookstores which cater for international customers (as opposed to just US).
Hopefully the 302 will have these features

Still awaiting a review from CES!
I'd like to see the 302 physical design be closer to that of the Sony PRS 600. The pictures I've seen of the 302 make it look like its bigger than its needs to be. There is a lot of space below the screen, which could be decreased.
One last thing: a 7" or 8" screen.