I'd say Wii U is the best bet at this stage, with a price cut to sub $300 inbound and MarioKart out in the spring to boost the slow season. XBOne at $500 is much too expensive to be a volume seller, PS4 will really have to capture imaginations and hype to sell at $400-$500. Most games for the newer systems are already available on PS360, and the exclusives aren't really system-movers.
So for now I'll say Wii U. The Nintendo really needs a Zelda, EA support and a new casual title to do really well in 2014 though. At least one of the unannounced titles from Nintendo 1st party also needs to be fun and charming and appeal to a casual audience, and make the Gamepad look cool. If these things happen it should be a very good year for Wii U, if not it should still do OK and probably sell better than the pricier PS4 and XB1.
