The wait for a DVD of Ong-Bak 2 with English subtitles is over.
And it comes not from Hong Kong. But from Keris Video in Malaysia.
HK Flix has it, and "all product features ... have been physically verified by HKFlix staff."
A further note says: "This DVD is labeled as Region-3, but is actually all region. The English subtitles are not advertised on the case, and are not available in the menu. To access them, you must use your remote while the movie is playing. We have manually confirmed that the subtitles are of excellent quality."
I should note that Chocolate, a much-sought-after "sister" film to Ong-Bak 2, also had an English-subtitled release in Malaysia before anywhere else that went out of print after just one pressing, and this could be a similar case.
So place your order now, if you don't want to wait for the eventual U.S. release by Magnet or whatever labels are releasing it in other English-speaking territorities.
Or you can get the Thai DVD and do your own subtitles. Bangkok 1080 has details on fansubs.