I agree that one shouldn't make too much of the warnings regarding either the Sanam Luang area of Bangkok (I reiterate - for February 4 ONLY) or Samui. Re: the latter, I have heard from a number of sources that Samui is having its difficulties and is not quite as pleasant as it once was. Recently a Thai friend left Samui after only a couple of months because he thought there was an unusually high prevelance of yaba usage among the working folks. I certainly don't advocate not going to Samui, but if one is trying to decide between Samui or another beach resort area in Thailand, I think it is something to consider.
As for this Saturday's anti-Thaksin rally, it should be interesting. Mr. Thaksin has been rather heavy-handed, with sometimes fatal results, in his attempts to retain and aggrandize his power. I hope everything comes off peacefully, but it is far from a certainty.