There still remains an air of confusion as to whether the Wii U will support more than one Wii U tablet controllers but according to Develop the company is hard at work trying to get the device working with two. The anonymous source has stated that Nintendo has nearly fixed the problem of supporting a second tablet, but it’s highly unlikely it will ever support four tablet controllers
“Nintendo now know they absolutely need to support two tablets.”
“At E3 they didn’t commit to this, but they know how important it is to make it technically feasible to support two screens. Even if that affects framerate, as a developer and player, I don’t care. It needs to work. Developers will design appropriate games for this. If you’re building a quiz game you’re not going to give a shit about the framerate.”