Right on the back of the confirmation that the Wii U is substantilly more powerful than the current generation systems, and a true next gen system, and right after the leak of the new Wii U controller, which features clickable analog sticks and analog triggers comes another great confirmation. From the good folks at GAF who are in the know:
I double-checked to be sure.
"So far we know for sure that can be simultaneously connected 4 Wii Remote Plus, or at least 2 WiiU controllers (but not learned if they can be linked together, ie 4 Wii Remote Plus and 2 WiiU controllers at the same time)."
"We played wireless, so yes, it had battery inside." Chris1962
More and more, this is turning out to be a system I'm very interested in.