With the continuing decline of Wii sales — mostly because everyone owns one at this point — Nintendo is expecting big sales for the Wii U. Across both consoles, they expect to sell a total of 10,500,000 units before the end of March 2013. They over-shot their estimates for the 3DS. Maybe this time will be different.
Source:
http://wiiublog.com/nintendo-expects-to-sell-10500000-units-of-the-wii-and-wii-u-before-end-of-march-2013/