I don't think it will surpass 10 million, but heck I'd say definately over 7 million. Once Nintendo launches their better games and after E3 2013. I think the console should pick up some sales.

You are crazy. That is a just wrong prediction, whether joking or not. Without doing any maths i say 12m.

It's going to top 10M in CY 2013. Wii U should have atleast one AAA title to boost the sales before the end of march; Wii Fit U.

You're not allowed to revise this prediction once the lineup is unveiled, MBP.

For comparision sake:
Wii 2007 - 16,553,289

Wii U going let's say 6,999,999 will means a 58% drop from Wii second's year.

Edit:

You should quote the OP to keep it original.

It depends. If the first few months with 2013 are littered with announcements for new iphones/samsung phones/next box etc there is a chance that the wiiu could sell less then 7m. A slim chance though as it's already hit 2m. I estimate that the life sales of the WiiU will put it somewhere inbetween the GC and N64, as long as 2013/2014 sees another console release and a continued popularity in iPhone/Nexus/etc products. 

Will that boost sales? I can't see people feeling the need to upgrade wii fit to wii u fit. It's not like you bought Wii Fit for the graphics, so why upgrade? This is the major downside nintendo never considered when they focused on the casual audience; getting them to upgrade when you are no longer the "in" gadget is incredibly difficult. 

I actually don't think those things will matter very much.  The people that want a Wii U are not going to suddenly decide not to get one just because some new phone (with the tiniest increase in something new over the last phone ) was announced.

New console announcements....maybe.   But largely it seems that consoles sales tend to be not be deterred too much by competitor consoles these days.   All 3 last gen consoles over 70 million.  

It's not the graphic increase but the little device it comes with that is going to be the sales driver.   Go look up the game.  It's kind of intriguing.  Certainly not the level the first game was but it should sell well.

The thing is you have to consider who wants a wii u. All I can think of is die hard Nintendo fans. Anyone who is a casual who enjoyed the wii is probably more inclined to play on a tablet/phone then cash out on a console. Are there really many die hard Nintendo fans left? The Wii would have deterred many new potential fans by offering the least of the 3 systems, meaning that gamers will most likely already have a 360/ps3, and therefore why upgrade to something which ash the "tiniest increase in something over the last" console?