Well but so far Mario Kart seems not be able to keep selling 150k a week. Of course there are apparently supply constraints in America, but were also only in the second month of the year, and you are expecting 150k a week for the first six months.
I think it will fall a little faster, especially when Wii Sports Resorts is launched, and I am quite sure that we will see weeks in 2009 where MK sells less than 100k, maybe already in the first half of the year.

Anyways, I think we had that debate already in another thread, and it is really hard to judge those games sales since those things haven't been seen before. Of course I'd love to see MK Wii sell 30M, but I don't think it is reasonable to expect this before it even reached 20M.

Edit: VGChartz deleted my post, so I decided I'll rather update it bi-weekly than weekly, as the changes will be far larger then, and worth noting.

I'm bumping this so I'll actually remember finishing the updating. I have only updated the X360 and Ps3. If someone isn't OK with an un-finished thread being on page 1, just lock it and I'll make a new and finish it later.