The PLAAF wants the J-10. The JF-17 is not as good. They will use it to replace the old fighters in large quantities. Kiwifighter is right, the PLAN might want to buy many JF-17s to replace their J-7s. There are too many J-7 so replacing with J-10s would cost too much $. So they will replace them with the cheaper less capable JF-17
We may have to wait and see. The way the PLAAF procures now raises some questions.
For the high end, they have the J-11B.
For the strike fighters, they have the JH-7A, though that may be challenged by the J-10S and the J-11BS (twin seater) in the future.
From mid to low end, you got the J-10.
The low end needs more explanation. They also have the updated J-8F/H, which is still being produced. The upgraded J-7G is still being produced but it seems to be on its last legs. Advanced trainers like the L-15 and the JL-9 are also getting a bit close to the JF-17.
So you have a fairly crowded situation here which may have some politics involved. I suspect the nature of how some contracts are made and distributed is intended to subsidize different regional firms and their community job markets.
For example, why just kill the JH-7A and add multirole versions for the J-11B and J-10? You can't because you may need to subsidize the guys in Xian, and not give the business entirely to Chengdu and Shenyang? Hence I see the JH-7A going to be staying for a while. The guys in Xian also make the updated H-6s.
So who should get the contract for the "cheap" fighter below the J-10? At the lower level, the JF-17 is facing the updated J-8F. Technologically, and in the viewpoint of efficiency and flexibility, the JF-17 is better. The J-8F however, brings to the table, the capacity for brute strength---sheer speed and high altitude performance, while being already a familiar item with a ready logistical base.