Encontré en un foro una explicación que dan de las diferencias entre el Streming de Vita+PS3 vs. WiiUMando(3DS)+WiiU:
PS3+Vita can't instantaneously swap out images back and forth. Also, there's very few developers who would even do it due to memory constraints the PS3 has (i.e. Sony's the only ones who could do it) in comparison to 360 and Wii U. Most developers won't enough memory to allocate for both on PS3. This isn't really a "can't do" but a "won't due" because of their own limitations. But let me continue.
Also there's a problem with lag created by the PS3's wireless capabilities, which aren't great. Streaming a lowered-resolution PS3 game (meaning less detail visually) to Vita becomes a significant problem at anything over 5 feet and cuts out at anything over 20 feet locally. Wii U on the other hand has no problems with lag until you reach the 30-35 foot barrier and cuts out at around 45 feet. This is because PS3 supports wireless g whereas Wii U supports wireless n. Also, Wii U doesn't lower the resolution for the screen, it just shrinks the native image (If you've seen the videos of the Zelda demo and NSMBM, you know what I'm talking about).
So no, PS3 + Vita can't do what Wii U does, and acts quite a bit differently. More importantly they'll be treated differently by the developers.Fuente.