No man just keep the WiiU. When you sell it you and those games you really want start getting closer and closer to their release dates you will be itching to sell that Playstation for a WiiU. I don't sell my games anymore because when I was younger I used to sell a lot and noticed I always bought them again not too far in the future because I missed them. Just stick it out and wait for Smash and Mario Kart, you most likely will not be disappointed and it will feel great having your hands on the game after waiting so long. Plus remember we have Super Mario 3D World coming out in a few months and Pikmin out next month. Oh and Wind Waker. I am sure these games can hold you over and once you start getting new and great games it will cure that need to get another system quick. I know exactly how you feel I have been like that many times but after I just held onto everything I have it helps. I started making collections for my systems instead of selling to get new games I was dying for. And that is a real satisfying feeling. So just hold out dude, you won't regret it.
I've definitely regretted selling many games when I was younger, games that are really hard to find now. Just build a good collection, it's a really satisfying feeling. And yeah, the Wii U doesn't have a lot going for it now, but neither won't the PS4. If I recall well, the PS3 struggled a lot for the first 2/3 years between solving some hardware issues and getting a decent game lineup. The Wii U is definitely going through that phase now and to fool ourselves into thinking the PS4 and Xbox One are somehow 'superior' to those issues is just silly.
Yeah, the PS4 looks good now but I bet it'll look even better in a couple years with a hardware revision and a more robust game lineup. Meanwhile, you get to enjoy your Wii U and all the amazing Nintendo exclusives that are coming this year and in 2014.