I think that WiiU can come back if great games are made.
Xbox One is way too expensive for the moment (500€ in France)
PS4 isn't really interesting for me.
(I liked Sony during their PSP and PS1/2 eras. But they got way much too "arrogant". The quality that I like in Nintendo and Microsoft is their "discretion" and the fact they aren't considered as "living gods", but as game producers, etc. PS: If you don't know what I'm meaning, check some french forums about the PS3-4.)
PS4 is trying to make people pay for the network. PS+ and PSN is a combo. But I'll have to check the prizes.
---> PC and 3DS for me. Perhaps WiiU can win. But I don't think the two others can really "win". They are at their "apogee" and if they fails (making bad games/ things like that), they will REALLY be hurt. Not Nintendo, thanks to the (now) discretion of the WiiU.