Go.
Bangkok's insane and those beaches are among the most beautiful I've ever seen -- rent "The Beach" with Leo, which was filmed there (Ko Phi Phi & Ao Maya) and you'll see what I mean. But... that area was ground zero for the tsunami, so I don't know what it's like now, but I'm certain the Thais will flip out having tourists returning.
Look into one of the round the world fares that Cathay Pacific or Air Malaysia offer. If you find one where your hub is Bangkok, snag it -- these things used to be only $1K or so.
Hit Lonely Planet's forums for more detail. If you start a thread there with "planning 14 days in Thailand, what to do" you'll get the best & most current information available. You might want to buy their Thailand guide beforehand, too -- it's the best.
Go!








