All the talk of supposedly imminent sale of J10 to Pakistan is overblown by the media. In fact there probably has been no official negotiation over J-10 sale. People particularly the russo/india media, made big fuss over the supposed Mig29's triumph over JF-17/J10 in Burma, but the truth is more likely, just like the supposed sale of J10 to Pakistan, China was not involved at all.
Here are some more observations:
1. J-10 in its current state is not ready for sale. As long as J10 uses russia-supplied engine, a foreign sale is impossible. And with WS10 currently seen only on J11B, a WS10 powered J10 also doesn't look likely in the near future.
2. J-10 is, like Type99 tank, or 054 frigate, mainly for the domestic market. Currently 1 regiment of J10, around 28 aircraft, is formed each year with the PLAAF, don't think Chengdu can produce more than that.
3. J-10 is, even in the up-coming B-version, doesn't offer anything F16Block52/60 can not offer. And nor is it terribly cheap, so why should Pakistan go after an unknown aircraft while a better/cheap(read US-subsides) alternative is already in the fold.
4. J-10 was certainly never offered to Burma. It's also questionable if FC-1/JF-17 was offered either with the latter's operational status still being a question mark. Mig29, on the other hand, despite being outgunned more than often going against western aircrafts, is a known commodity, and suits Burma's needs perfectly. Also the aircrafts could be refurbished ones and thus ready for immediate delivery.
5. A country like Burma, when it chooses to buy fighter jets, performance is never the most important criterium. Economy and politics are far more important. Seeking to diversify its weapon source, buying some cheap but still fairly sophisticated (by south asian standard) jets from a powerful country is only logical. If you think Burma went through a rigorous bidding/evaluation process like India is with the MCRA purchase, then you are totally wrong.
6. Finally I don't think J10 will ever see service beyond the chinese border. China is not desperate for cash, and by limiting J10's service to the PLAAF, potential adversaries will have a harder time to assess J10's true capabilities.