This looks like a compact F22/JSF, optimized for air to air. No doubt thrust vectoring will follow.
The larger J-20 is able to carrry a lot of fuel and war load internally. Probably to "project power" or however the cold war folks used to name it. I would not be suprized to see a two men cockpit for the J20 later on and suitable long rang air to ground (ship) missiles.
http://img208.imageshack.us/img208/2818/j20f22comp.jpg
Now up for a new tanker fleet, based on the H6-K, Midas or .. another suprize.
There also rumours / pictures there's a third aircraft under development, folks say it has different dimensions then this Shenyang aircraft.