Ideally it wouldn't BREAK existing games, in those cases, it'd just be dead, or maybe echo input as if it were the buttons or the left stick itself?
Games would have to be designed for 1 stick and 2 stick options, yes, but it would be nice to HAVE the option there when possible.
I was holding off for a redesigned PSP, but... I'm pretty underwhelmed. I know rumors get carried away, but I guess I got too excited with what had been heard, which had a lot of truth to it, but not to the degree we saw. There IS internal memory for caching games, but it's only 64 MB, not 8 GB. The battery life is better, but we're not clear by just how much yet. It's lighter, but the overall shape is still the same, and some inherent problems remain. And the "wishlists" generally went unanswered. It's better, but it's hard not to want something more.