This is all just rumour for now but it comes from the same source that tipped a second 3DS circle pad among other Nintendo things.
The tipster - talking to previously reliable Nintendo leak site 01.net - has listed a number of hiccups and hurdles supposedly causing problems for Nintendo's on-going development of Wii U, including claims the final hardware has been "rushed through the door".
"According to our source, it seems that the final architecture has been rushed through the door, with undesirable consequences," the 01 report reads.
Those consequences allegedly include "inadequate" streaming and wireless functionality integral to the Wii U's innovative design, the source continues, and speculation that the console's main chip set "may be a tad too cheap."