I am also really excited by this; anything that pushes handheld AR will be a good thing for those of us currently engaged in it (and it’ll give my students more job opportunities!). There is the practical issue of creating “good handheld AR games” that are practical for mass marketing and consumption. The DS/PSP/Gizmondo aren’t powerful enough to do “real computer vision” (like the PS3 could do), and so some sort of physical props (e.g., cards with markers on them) will be needed. As soon as your start requiring props, that makes the games less portable … a conundrum to be sure.
Hopefully, some of the students in the “handheld AR game design” class I’m doing at GT right now (in collaboration with a class at SCAD Atlanta) will come up with some compelling examples and help drive interest!