Still haven't played my copy of Assassin's Creed IV: Black Flag. I probably will soon, just cruising through Knack at the moment.
Wouldn't really say that the Wii U is on a roll. It has picked up sales, but it is probably because of the holiday season and bundles. I don't believe every sale made was a "We have absolutely got to have a Wii U" situation. We'll (not) see soon enough how many of those buys are long term investments for those families. It will probably be a lot less than the Wii, but then again it's not nearly as prominent as the Wii was.