Well, it sold 3.6M last year in Japan, and it is tracking slightly below that now (around 10%), so 3.5ish M this year seems realistic.
That means 2M more for this year, bringing it up to 8-8.5M for end of the year.
So far this year it has sold 1.4M, and as it needs about 1.8M, I'm going to say 60 weeks from now, or end of June '09.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS







