I had a chance to see a non-interactive video of Kid Icarus:Uprising on the 3DS at E3 last year and suffice to say, it looked pretty nice with the 3D depth of field. This could definitely be a killer launch title for the 3DS.
Although with the reported 3-4 hours of battery life of the upcoming handheld system, I kind of wish they would have just released a proper console instead.