Eh, I honestly might consider it depending on the holiday releases, and then pick it up again in the future when there's a price drop and/or stellar bundle. My reasoning:
Put Wii U forward toward PS4 with a nice little Gamestop bonus (games I might keep depending on trade-in value with bonuses) and get a system I'm much more interested in. I LOVE Nintendo Land multiplayer... but some of my friends have it, and I'll still have my Wii and controllers. I'll still get to have a blast with that. And I'll pick up Rayman Legends on another system. And I can play Wind Waker on Dolphin

(Edit: Yes, I know it looks different). Really, they'd have to announce 3D Mario and/or Smash for this Holiday in order for me to keep it. I fucking love Bayo and Mario Kart and whatnot, but I'm a lot more interested in checking out some of the awesome independent offerings that PS4 will have, maintaining my PS+ service bonuses, having a next-gen console with better graphics that also won't block used games, etc etc.
I would definitely get a Wii U again later. Nintendo has reeeaaallly let me down over the last few years in so many ways, and I definitely jumped the gun on the Wii U. I DON'T regret the purchase, but for the sake of value and thriftiness, I'm considering it depending on what happens with E3.
I am not going to Day 1 Durango just like I didn't the 360. I like MS first party stuff just fine (never used Kinect though, and I'm really interested to see what happens in the future here), but it's their XBLA games that I really enjoy.
Anyway... all that said, it really depends on E3, and I'm betting Nintendo is going to convince me to keep my Wii U... Which just means I'll have to buy a PS4 day 1 without the trade-in discount. C'est la vie.