Is there a reason why you want an Atom, a second CPU and a video card? Especially the second CPU?
Or are you just after some more power than the current generation?
My solution wouldn't be to try to stick desktop hardware into a handheld, but rather go with a OMAP 3x or a NVIDIA Tegra etc.
They won't play Crysis, but they will play Doom and Quake 3.
And then in two years, maybe we get to play Crysis (if they open up the source).
Handhelds will always lack a few years after desktops, it's easier to make something big, hot and power hungry first, and then tone it down.

My biggest issue with the current (and next generation) devices is the lack of a good dockingstation with DVI and VGA out.
I recently abandoned my desktop PC for a Laptop + Dockingstation solution, and we are rapidly approaching a situation in which a small handheld could serve most of my basic computing needs. The TI OMAP 3 series isn't quite there, since i would need 1920x1200 resolution, but i hope that in 2-3 years this will be possible.

Bye,
NsN