He talks about it here:
http://www.twitchfilm.net/archives/002144.html
In all honesty, Yen has little to worry about from the Thai market, but if the result of his worries is a film like SPL or DRAGON TIGER GATE or sequels to same, more power to him! Tony Jaa seems to put out about one film a year and, fantastic though they are, they're the cream of a very large and generally very poor crop. The VAST majority of Thai films are absolute chores to get through. For every SHUTTER or ONG BAK or TOM YUM GOONG made by people with firm grasps of the finer points of filmmaking, there are about twenty poorly made "comedies" (tranny and otherwise) and jaw-droppingly toothless "horror" films that will rarely be seen outside of Thailand's borders. From a screenwriting standpoint alone, the Thai industry still has a long way to go to catch up to even the Hong Kong market.
If anything, ONG BAK (and to a lesser extend BORN TO FIGHT) didn't so much teach Hong Kong filmmakers how to make martial arts films again as it reminded them of an area they'd neglected a bit over the past few years. No that there haven't been some decent martial arts battles in just about every year's output, (like 2002, or HOUSE OF FURY), but it's nice to see the real pros go at it instead of the usual pretty boys (and girls).
What did LAST SAMURAI do, exactly? I missed that one....