While there have been some warranted rumors floating around the Internet after E3 2011 regarding the Wii U's supposed ability to use only one controller after Shigeru Miyamoto stated that the system was designed for only one controller, word has come that the hardware and price for the system have been far from finalized and we'll probably have to wait until E3 2012 to see the finished product. But don't worry, you'll be able to use more than one controller.
According to IGN, Satoru Iwata, Nintendo Global President, had a long Q&A session with Nintendo's investors much of which apparently focused on the aforementioned problem especially after Nintendo won this generation based on family gameplay. Why should they endorse and invest their money in a system doing a complete 180 and focusing solely on single player gameplay? Then you wouldn't be appealing to the hardcore or casual gamers. You'd be appealing to the Nintendo offices I guess but nobody else.
Reggie Fils-Aime had previously said that two controllers will be able to be used with the system so that laid many fears to rest but many were still scared because of Miyamoto's comments during E3. Iwata takes the sides of both of these executives. He says the system is designed for only one player and that's what Nintendo is focusing in on right now but two controllers will be able to be used. That's a good idea since the casual gamers only need one game like Wii Sports for a system to take off but hardcore gamers are the ones that keep going out and buying games. So this is probably a good idea out of Nintendo.
Whether you see this as them trying to have the best of both worlds or trying to have their cake and eat it too, Nintendo is trying to cement its place as the leader in video game consoles and their earlier release and innovative concepts give them a great chance to do so.
Whatever else you hear about one controller, just wait. The hardware isn't final and the finished product hasn't been revealed yet. You're going to be able to use two controllers. It makes too much sense to leave out.