2 Analogs.
Touch screen maybe?
I guess a psp2 would just have different hardware changes, and maybe better looking games (if possible).
MORE RAM.
More processing power to run N64 emulator.
More processing power to run PS2 emulator
![Very Happy :D](./images/smilies/icon_biggrin.gif)
A built in messaging system to send messages over psps.
A thumbpad keypad thingy to send messages faster, like on one side it is a psp, then you flip something and a keypad appears.