How many PS3s will have been sold in NA by the end of this gen?

[JGarret]

Let´s assume the end of this gen (as far as home consoles go) will be around November/December 2012...according to NPD, the PS3 has sold around 12.5 million in NA (or just the U.S.?) as of March 2010...31/32 months from now, do you think it´ll have passed 20 million?