The wii u sold just over 3 million for the launch period but then sales dropped off a cliff edge and didn't get to 3.5million until the end of the financial year. It was generally considered that Nintendo fans had bought the console with great enthusiasm at the beginning but it couldn't find a wider audience for the product after the launch and sales numbers were from then on quite low. Here in the UK the launch numbers for wii u were only 40,000 for December.
I think the wii u had a big advantage of launching before Christmas though which is important in many regions.
I don't really know much about other regions but the vibe I'm getting in the uk is that it will fail horribly. UK like most of Europe is very keen on Playstation products and unlike mainland Europe Xbox is a big important brand too.
