At this point, it has sort of been confirmed, although there is some confusion on the subject. It has been stated that Friend Codes are no more in the Wii U's online system, so that's a step in the right direction. That means username-like formatting for friend related functions.
Now on to the confusion part. Someone from Nintendo- I believe he's the president ok Nintendo of UK- said something along the lines of "The Friend Code system is much more refined and very similar to the XBox Live system." We can only assume he was misinformed, doesn't know much about XBox Live, or there actually ARE Friend Codes, but they're much better.
So, bottom line, either there's something VERY similar to XBox Live formatting, or there's a new spin on Friend Codes.
EDIT: The only thing we know about the Wii U's release date is that it is not coming out April 2012 and sooner.
Hope that answered your questions!
