According to a rumor from 01net, Nintendo is facing some issues with development of the new Wii U console. Nintendo is said to be having hardware issues with the new controller and its wireless connectivity, which is why units shipped to developers currently have the Wii U tablet controller wired to the console, instead of operating wirelessly.
The reasoning behind the hardware issues are said to be due to Nitnendo’s “low cost” approach to hardware, which is now backfiring with the console and controller not performing adequately. These reports should be taken with a grain of salt, as they’re unconfirmed (and Nintendo will most likely never confirm such things).
The Wii U is scheduled for release during the Fall of 2012, just over a year from now.