Dai_Farr
regrettably the chances of a co-ordinated SAR effort are remote. Given the mutual suspicion verging on hostility and the asian mind-set of not going into a position where they might lose face, I reckon each country is searching it's "patch". Now the USA will arrive, along with Oz patrol planes and they'll probably co-ordinate between themselves, but just tell the locals what they're doing. Don't under-estimate the need to maintain face. I live in Asia and that aspect has to be understood well.
On another idea - is anyone looking on land ? If the plane continued northwards it's not beyond the bounds of possibility that it ended up in the Vietnam/Cambodian mountains.