China offered J-10s to other countries like Burma, so Turkey isn't absolutely off the list. Countries like Sweden, Yugoslavia, and even Pakistan have operated Eastern and Western aircraft simultaneously, and there are ways to make that work.
The point is moot because Turkey hasn't even expressed interest in the J-10, because this isn't what they are looking for. They are looking for something they can jointly manufacture, in the 4th Generation lightweight category. JF-17, F/A-50, and JAS-39 Gripen all classify as 4th Generation lightweight fighter aircraft. These three aircraft don't offer equal capability, and JF-17 doesn't seem to be on the top of the list for Turkey, there are factors that put these two aircraft above the JF-17, and there are factors that put the JF-17 above them.
For example, it's flight envelope would likely offer better manouverability over the Gripen, as delta-wings aren't as manouverable especially at sub-sonic speeds. Second factor is being US-independent, and this may or may not be very important to Turkey(seems like the whole reason they are going for this semi-indigenous route is to gain some independence, moving away from the US designs without compromising on performance too much).
Given that their Prime Minister even talked about the JF-17 publically, and how PAF officials publically talked at Farnborrough about Turkey's response(and request for presentations to their TuAF officials), and also about the PAF being invited to fly this aircraft at TuAF's 100th anniversary, I'd say that this aircraft could be a contender. I think our Chinese friends underestimate this little bird a bit, because it is a light aircraft that is not in the same category as the J-10(medium) and J-20(5th-Gen heavy-fighter). Or perhaps we tend to overestimate it because this aircraft's performance capabilities have been a pleasant surprise for us(out-performs the F-7s and Mirage aircraft it is replacing in avionics and flight-dynamics, being a small nimble aircraft).
The main questions determining whether it is a real contender, or just something the Turks use to make the Koreans/Swedes more reasonable, would be the aircraft's future block's avionics/radar package and how it compares. AND secondly, the engine - Russia's engine is not as good as US offerings, plus Russia may not be keen to enable it's competitor to sell to Turkey. WS-13A(or possibly B) could make a huge difference.
