The PSP consumes 7W while charging the battery and simultaneously playing. We can assume that's peak power, as it will consume a lot less than that while not charging, running off the battery alone.
The 4650 + Celeron 440 combo has a TDP of 105 83W. Even if real power consumption is half that, if a PSP lasts six hours then this new handheld would last an hour on a full charge. With that kind of dissipation it would get seriously hot, and the form factor just wouldn't hold even very stripped down versions of those things.
Basically it would need a laptop form factor and would not be a console competitor.







