01net had published a report from an anonymous, trusted source who claims that the Wii U's hardware and architecture has been "rushed out of the door" ... and that it's simply not fit for task. Apparently communication between the wireless tablet and the console itself is intermittent, despite three separate prototypes being tested and another on the way. Developers are also allegedly being constantly bombarded with new software updates, making optimisation difficult. This may cause the Wii U to be pushed back from its projected June 2012 release to September.
Naturally this is a rumour and should be treated with intense suspicion... but 01net's source is the same mysterious figure who outed the now-confirmed 3DS Expansion Slide Pad a few weeks back. They've proved themselves reliable before, and we'll keep an eye on the situation.
We've reached out to Nintendo for comment.