In order to not move backward: 1. DO NOT increase the size of the tablet (from N810). I like the N810's small and thin profile. 2. DO NOT remove the keyboard. For God's sake that was an improvement from the N800 and some people want it gone.
5. ADD A PIM SUITE. There is just no reason not to. The whole "but this is not a PDA" excuse just doesn't fly. The customer is always right and many customers say they want a PIM.
Oh, and one more thing. The N900 should have a screen flush with its surface. I hate the way the screens on the tablets are recessed.