I think 2017. We could see both consoles under 299 by that point and there will be a lot of huge games at that point (ES7, and TLOU 2 I think will hit that year)
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut