Raven on 17 April 2015
Waiting for a price cut is always beneficial since it allows you to buy more of the games you want once you finally do purchase it. It depends on how much you value the current library of the Wii U though. If you feel its worth the price for what you're getting, then go for it!
I wouldn't worry about the NX too much though, I have a feeling it'll be a portable device. Even if it were a home console, unless Nintendo goes PowerPC again I don't think it will be backwards compatible with Wii U anyway.
