misterd on 11 May 2007
I think the "guess" here is referring to the supposition that the last month of sales is an accurate predictor of future sales. Of course anyone with a basic grasp of statistics understands the problem with this (and you address this in your post), but these same people should also be able to recognizethis as a "this is the best we have to go on" situation.
One could argue that external factors that affect one console will also affect others - holidays, economic slowdown, etc. Even new game releases (I'm not sure Lair and Heavenly Sword are going to be system sellers) will likely buffer out unless one system has the next GTA3 waiting to suprise us all.
