The more information that comes out the more it seems Nintendo is putting into the WiiU and offering 3rd party companies to put into the games for the WiiU...
Though several games will be released a bit later (Due to the launch date of the WiiU) it may be well worth it to wait for the WiiU version of the game if you are a fan of the game of plan on getting a WiiU at all.
first off the the WiiU offers several play options on many of the games such as the ability to play with the Gamepad which allows for the inventory screen to always be open and in front of you instead of pausing the action in any way to switch weapons or anything els..
2nd, you have multipple play options to choose from to include the game pad, the Classic controller pro, and even the wiimote and nuchuch in moste games.
3rd, it seems like a majority of the games (especially FPS') are offering the option to play in full 1080p on the big screen of switch to the Gamepad to free up the TV for those who have families that only have use one room in the house for the gaming system.. So you can still play your game and the TV is still free for others to use.
But based on what Nintendo has talked about before (offering it's video and other online services for free at no additional costs) and more recent new by the developers of Call of Duty who are working with Nintendo to try and offer all DLC and online play on the WiiU for Call of Duty: Black Ops II on Wii U FREE unlike the other systems that will still requier a paid cost, it may be even more worth it if other game developers follow along as well.
Here's some lite reading on the Call of duty subject:http://www.examiner.com/article/wii-u-to-sport-black-ops-ii-elite-elite-to-be-a-free-service-for-gamershttp://blogs.mercurynews.com/aei/2012/10/16/quick-thoughts-on-call-of-duty-black-ops-ii-on-wii-u/
Also from what has been said so far and shown, many games on the WiiU will offer additional content not found on the other systems as well as the higher quality (possible) sound and graphics.
The question is... Will you already be planning on getting a WiiU or will extra content and not having to pay for additional DLC on games you already intend to buy intice you to get one? Also, will this lead Microsoft and the PS3 to respond in kind? Only the respons of their fans and time will tell.