I'm honestly really curious, how they will try to move a twin-stick shooter such as Super Stardust HD over to something like the PSP. I guess with Geometry wars you could still somehow combine the control options of the stylus and the analog pad, but on the PSP? Are there any games out there, that have already solved this problem?

when was this announced?

Looks like they will be using the d-pad. It CAN be done well, I remember playing this style of shooter on a keyboard and having loads of fun, the controls will need to be drastically changed though to suit it. Lets just hope they nail it! Cos I REALLY want to play this game, and have fun while doing it hehe