c0rd on 26 October 2008
If it's going to happen, I'll say this much: it won't be by a Playstation brand. Sony needs to completely change their strategy if they want a handheld that can match Nintendo's. I still doubt they're capable of ever coming up with something that can match Pokemon, Super Mario Bros, or Brain Age / Nintendogs. These games are monstrous system sellers.
@Nickelbackro: Not even close. The Genesis took quite a lot out of Nintendo (their NES/SNES users). The PSP looks like it's hardly affected Nintendo's handheld at all, seeing as how it'll be by far their best selling system ever (with the Wii being a possible contender).
