First, if there's one thing I've heard PSP owners complaining about and asking for since day one was a second analog nub. The PSP's analog nub is pretty good already, so sticking another one on, a la the Dualshock's layout would be a no-brainer for the new handheld.
Second, I would like Sony to continue releasing games in physical format. This is highly unlikely, given the release of the PSP Go [although catastrophic failure; the PSP Go's worldwide sales didn't even pass 900 last month!], they will probably switch to a digital distribution-only system. I'll join with all gamers in a resounding "Up yours, Sony!" if this happens. Plus, a higher storage capacity makes more options for games. Speaking of high storage capacity...
I really, REALLY hope Sony enables the Memory Stick XC format in the PSP2. In case you haven't heard about it, let me fill you in. Actually, scratch that. A picture is worth a thousand words. This should outline all my reasons:

2. FUCKING. TERABYTES.
Yeah, this would be awesome for storage, and for homebrew/backups, when the PSP2 is hacked.
Lastly, this may sound odd, but for its' own good, I hope Sony holds off on making the PSP2 as long as possible, so the most powerful technology feasible can be used in the system. What I really want out of the PSP2 eventually is portable Gamecube and Dreamcast emulation [via an unofficial emulator, of course], and I'm predicting an official PS2 emulator from Sony, much like the PS1 emulator currently used by them on the PS3 and PSP. I know that DC emulation will become somewhat possible with the release of the Pandora, which gives me hope that the PSP2 will push it over the edge into comfortable playing speeds. Oh, and for all you who are skeptical about the PSP2 ever getting hacked, remember this: With a few exceptions that are mostly attributed to personal definitions and interpretations, every single mainstream console that takes unique data mediums [by which I mean not pre-programmed systems like the Odyssey], every single mainstream game console has gotten a method of running homebrew and backups on it at some point. The PS3 doesn't really count, because its life span as a console is not nearly over yet.
Next gen is gonna be fun.

