Despite its continued success in Japan, PSP sales elsewhere have fallen off a cliff. Software sales are still woefully low – and it’s best we just not talk about how badly the PSP Go bombed. But if rumors are to believed, there’s a chance we may see the PSP2 announced at E3 this year. And with Nintendo continuing to dominate the handheld space – with a new 3D model on the way – and Apple having quickly become an imposing force among casual gamers, Sony has to be feeling the pressure. So regardless of when the PSP2 does come – whether this year or next – what does Sony have to do make sure it’s a success? A Second…