This rumors comes from 01net who correctly predicted the 3DS attachement announcment. With that said, they have said some other rumors that have gone on announced. So take this with a grain of salt.

“According to our source, it seems that the final architecture has been rushed through the door, with undesirable consequences.”

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.”

“So far, the wireless functions simply do not work at all,” it continues, claiming that as a result, developers are working with a tethered controller which apparently “still does not work properly”.

“Many developers are feeling lost, their progress impeded by a distinct lack of visibility, their working hours by the quasi-paced daily software updates.”