I'd also think it will be discontinued shortly before the next generation, so around 2012.
Think of it this way, during the month of June, NPD reported:
PS2-152,000
PS3-164,000
When the console from 9 years ago is still selling within 15k units of its current-generation successor, it has to be used for all its worth.
Leatherhat on July 6th, 2012 3pm. Vita sales:"3 mil for COD 2 mil for AC. Maybe more. " thehusbo on July 6th, 2012 5pm. Vita sales:"5 mil for COD 2.2 mil for AC."