Why hasn't this been reported yet? In an article on nintendolife?
They passed the 1 million mark as of 19 December 2012 according to Wikipedia.
http://en.wikipedia.org/wiki/Wii_U
I hope this isn't some fake info...
One million is a good number. And they achieved it in a month (counting NA release)...It's not exactly what they wanted, but this shows that 5 million by March isn't impossible.

