I did some rudementary math on this a few months back and calculating for the average monthly sales of each system since launch, going until 2010 or 2012 (I don't remember my cut-off point, but I think it was the latter), the Xbox360 would remain in second place, behind the Wii. The brief moments when the PS3 was actually outselling the Xbox360 did not show numbers sufficiently high enough to actually outsell the X360. When I did the calculation, I maintained, theoretically, that the average sales numbers would remain constant (which is unlikely). However, their sales will likely drop off at the same rate (%), and in the end, their total sales weren't far apart. I think they ended in the low 30-million-mark, roughly as far apart as the Xbox and GameCube were, with the PS3 in third. This means that, according to my "averaging" math at the time, the PS3 will outsell both the Xbox and GameCube, but I don't think it caught up with the N64.
I think I posted this over at GameInformer's forum.









