I guess I'll add my .02 cents;
*Automatic USB host mode (I guess a firmware revision can already do this)
*PIM and Sync
*Better camera, at least 2mps (I've read somewhere that the cost for a 1.3mp camera for BB phones costs $10)
*Longer battery life
*Bigger swap file
*BT Mouse support
*printing support

I know most of that can be done with scripts/hacks but it would be nice if it came as a default. Other than that, I'm pretty happy with the N800, the $200 average price per tablet is very affordable, I can see students lagging this instead of a laptop to classes... Schools would just have to provide keyboards per classroom seat instead of buying desktops. Nokia should jump on the bandwagon to sell their NITs along with Dell, Mac and (insert other pc makers here) to schools.