JF-17 production will start by early next year and will be at around 25-40 per yearIndia is not taking out all of its Mig-21 Bisons from its inventory until 2015~. They just have a lot of those fighters and they simply cannot replace them all. Its understandable.
My guess is that F-7s will also be not getting replaced, but Mig-21s are pretty good though, they have recieved some very decent upgrades in the last 5 years. Isrealis were also offering the upgrade version i believe.
I am wondering if Pakistan can find some upgrade for F-7 and can make them worthy for a little long period of time until we have all the JF-17s in place. I am sure this process is going to go slowly and wont be easy, but an upgrade for F-7 will just be helpful.