3 major things gonna make the Wii U the obvious winner:
1) Price: Sony simple can't compete with a $300 - $350 Wii U vs $500 (minimum) PS3 + Vita, unless you're a hardcore Sony fan you will not buy both systems just for cross-play.
2) All Wii U systems come with a GamePad, that alone makes all developers (at least most of them) develop games that use the touch screen, not every developer will use the Vita+PS3 crossplay functionality (mostly do to increase in dev cost). I honestly don't see many third parties use the Vita+PS3, only Sony first party tittles will use it, or Wii U games that may be ported at some point, like ZombiU.
3) We haven't seen all things that both system can do, but so far the Wii U have more unique functionalities, like the Panorama View for example (I haven't seen the Vita do that yet), for some it may seem gimmicky but it's something that will appeal to the casuals.
Nintendo and PC gamer
