They already have 90% of their resources focused on the PS4. 3rd parties will continue to support it for a year or two, but Sony is already moving on. They've almost completely abandoned the Vita, and the number of 1st party games coming to the PS3 between now and when it's discontinued will be countable on one hand.
The cost of developing has risen too much. The days of Sony strongly supporting their consoles for 10+ years is long gone.








