It was less than 15000 units away from 100000. Since they have moved up in the ranks, even if it is because everything is tailing off this week, sales shouldn't be falling off that much. Of course it is still early in the week but, I think we'll hit it.
I remember reading a post that someone had put up before saying they had contacted them via email and said it was figured monthly..
It would explain why it looks like only the more recent products are in the top rankings on Gamestop.com.. It keeps the older games in the lower ranks that way.