looks like an iphone4 that's been jailbroken and has some jailbreak multitasking installed... most of the jailbreak multitasking apps had interfaces like that before apple started multitasking. also the visual representations of the multitasked apps show to be in active states which means that it would be 'true' multitasking, which would go against apple's own view on iphone multitasking... unless due to the phasing out of the low memory 3GS they have changed their minds about how multitasking should be done...