Stumbled across this by accident:
Featuring an eclectic array of holiday tunage, there's only one song that overlaps with my Xmas mix (we'll just overlook have to overlook the presence of one Xmas song that I hate). Plus you have your choice of downloading everything in one ZIP file or cherry-picking individual tracks. A nice mix (and good quality MP3s, too).
There are also more MP3s of the non-holiday variety on the Making Flippy Floppy blog.