I already have the Wii U which I use very often to browse the internet and YouTube when I'm not on the PC, plus the Off TV-Play feature is really cool since you can do pretty much all on the GamePad.
As for PS4 and Xbox One -- When they get released in Slim models. I don't like their first-gen models they just look ugly, waste of space and problematic (Launch PS4 consoles are reported to be with a lot of hardware issues).
My consoles are all in vertical position (360, PS3, Wii, Wii U) so that makes Xbox One somewhat impossible to work since it wasn't designed to be like that... It's an 8th gen console and it can't.