I've been researching a bit as well because DS was also showing interest in WiiU.
From what various people at GameStop, Toys R Us etc. said - Wii is the least desirable platform - no multi play and graphics aren't as good. Xbox360 and WiiU have similaer graphic qualities, however the consensus is the XBOX controller is easier and better for Infinity game than the WiiU controller - they say WiiU is too cumbersome...
So I'm now thinking we can avoid getting a WiiU (only reason DS wants it is for the Mario Bros. WiiU game). He'll get Disney Infinity for XBOX 360 and will get into playing that and forget or realize he doesn't want a $300 gaming system just to play a Mario Bros. game when he still has his Wii System with lots of Mario games and XBOX 360 with Infinity plus the Disney Kinnect game...and then instead of wanting WiiU for Christmas he'll want Disney Infinity characters and discs and accessories and mom and dad will be running bowlegged to every store selling Disney Infinity to get the last package of the character he wants because it's such a hot game!!!
I'm going come in and offer a different opinion, if you're interested in hearing it.
Yes you're correct in that the Wii is the least desirable platform. It's the weakest hardware currently sold on the market, and because of it's limitations, the graphics are weakest of all the platforms that Disney Infinity is sold on, there is no 2-player option in any of the playsets (though there is in Toy Box mode), and there is also no online compatibility. (For either downloading Toy Boxes or playing with up to three others in Toy Box mode.)
However, the Gamestop crew is incorrect on two points. For one, the Xbox 360 and Wii U are incomparable in regards to graphics capabilities. The Xbox 360 is hardware that was released in 2005, while the Wii U is hardware that was released in 2012. There's a 8-year gap of enhancements and performance increases between the two. The Wii U is Nintendo's follow-up to the Wii, just as the "Xbox One" will be Microsoft's follow-up to the Xbox 360, released later this year.
However, since Disney Infinity is designed as a game that's meant to be identical across all platforms, it will look the same on the Wii U as it does on the Xbox 360 and Playstation 3. The graphical difference becomes more apparent in games that are designed specifically for the Wii U hardware.
Secondly, he's incorrect in saying that the Wii U Gamepad is cumbersome for Disney Infinity. In fact, it's the complete opposite.
Now, I'm not sure how much you know about the Wii U, so I'll cover the basics. The big thing that's setting the Wii U apart from its competition is the Wii U Gamepad, which is a 7-inch touch screen that's surrounded by buttons, offering the best of the worlds of tablets and controllers in one package.
Every game takes advantage of the screen on the gamepad differently. Some games will show a map of your surroundings on the gamepad screen, some games show your character's inventory, and some games show different camera perspectives on the gamepad screen, and more. It's up to the developer of the game to utilize this second screen as they see fit, and there's been some great usage of it in the 10 months that the Wii U has been on the market.
Disney Infinity utilizes the gamepad in four ways:
1) During playset gameplay, you're able to view missions that are available directly on the gamepad screen without having to go into a separate menu, meaning that the gameplay is never interrupted.
2) During playset and Toy Box gameplay, gadgets and weapons can be selected through a menu on the gamepad screen, again allowing you easy access to everything you have on hand without a cumbersome menu you have to scroll through on the TV.
3) During Toy Box building mode, you're able to view all the objects you have available to use in build mode directly on the screen, and you can tap what you want to pull into the game, instead of having to go through the menu.
4) During the entire game, you can switch the gameplay from the TV. This is a pretty neat feature that quite a few Wii U games offer. If the Wii U is connected to a "main" TV in the house, if someone else wants to watch television or otherwise use the TV, with a tap of a button the game can be played entirely on the Gamepad screen as if you were playing it on the TV. I do this myself sometime just so I can play in bed.
Here's a nice video showing off the features that the gamepad offers.
The Wii U itself is compatible with all his old Wii software and controllers, so you'll be able to replace the Wii with the Wii U and carry over everything he already owns without a problem.
I'm not here to try to convince you into spending $300 on an entirely new console at Christmas, but I've run into my fair share of Gamestop employees that can be bias against some companies while being overly supportive of others. I bought a Wii U on the day it was released, just as I did with the Xbox 360 eight years ago. They're both great consoles, but the Wii U has some great features that really set it apart from the competition.
Feel free to ask any questions you may have about it.
As a bonus, here's an interview with a Disney Infinity producer about the advantages of the Wii U version.
And I found a second one. Woot.