It lasted two weeks, which is more than a lot of people thought. Will it last three? I think so. due to supply restrictions for the PS4 and X1, and increasing holiday sales for Wii U, I'm gonna predict around 350,000-400,000 for all three consoles next week.

Wii U: 4.8mil
PS4: 2.5mil
X1: 2mil

That still over 50%. What about week 4?

Yes. Christmas should give them a nice boost in sales. With ps4 being short on supply and X1's price, I can see the wii U selling decently enough to maintain a lead, but I don't know for how long. Oh and I didn't know X1 sold 2 million already. Source?

Wii U is not selling great.

VGC has it at roughly 290k for November in North America, which is probably overtracked and barely more than the GameCube's November 2005, where it was on its deathbed and had basically no big releases at all (272k). That was the GCN's worst November from 2001-2005. 

It's probably the reason why Nintendo has not said a peep about their Black Friday sales -- 3DS was great, but they don't want to talk about Wii U. 

Wiiu is not selling great. Dude are truly a genius for working that one out. I am willing to bet no one else has. 

Anyhow on to the question asked in the thread. I think it can, barely. But then thats it.

Yes.

It should do

Probably for a few weeks, Wii U will need to sell something like sub 150K per week for the rest of the holiday season for it to lose the spot quickly.

until the end of the year

I assume so, but Nintendo could surprise and have 100 Million $1 Wii Us available, I bet that would sell out quickly.

Yup.