Woohoo, Activision can eat their words...
Though the numbers are a tad lower than the analysts projected (see
http://www.gamespot.com/news/6232261.html ) ; they were looking between 1 and 1.3 m for TBRB on all platforms, but with the numbers here and assuming a respectable PS3 # of 150,000, you're only looking at about 650,000 units. Sure, first month numbers and all, and we've got 2.5 months till Christmas, and they aren't nothing to sneeze at, but I think this was a little off from projections.
(Comparison number: 360 version of RB2 sold 363,000 on its release month)