PSP, I will post what I wrote on the other topic concerning it:.
Nintendo has it all right now for handhelds, although I wish they didn't. The Game Boy was the first massively popular portable gaming system, and it was amazing for everyone. All the people bought it. Ever since then, they have owned, just because of the momentum they created with the Game Boy. Remember the Game Gear? In my opinion, it was better than Game Boy and GBC, which didn't even come out until a couple years later. Game Gear didn't succeed because the companies were already with Nintendo.
Playstation was something new from the familiar Nintendo. It had the perfect timing. Cd's instead of cartridges, mature games from the start, pulled all the gamers in. N64 was probably Nintendo's biggest mistake in creating a console. It was lucky that Playstation became popular.
If N64 had disks and more mature games, the gamers would have stuck with what they knew instead of going to something different.
All the game companies went to the revolutionary thing, the Playstation.
And because of that momentum, Playstation 2 owned. (Coming out first also contributed to it.) And that was great timing, too. So not as many people went to the Gamecube.
X-Box has great specs and everything, but no major game companies going for it. The cool features were the only reason gamers bought X-Box. I have yet to play an X-Box game I truly enjoy, and want to play all the time.
Now, back to the PSP after my endless rambling.
I think Sony should wait to release the PSP. Build up the hype, let game companies realize that it has the potential to be a great system. Then, when GBA is starting to lose it's luster, (less good games coming out, mostly ports. People are looking for something new from Nintendo), hit them with the PSP. If it is released before the next Nintendo console, gamers would flock to it.
The PSP already has the specs to blow GBA out of the water. It should be the exact scenario of the N64 and the PS1 release era.