In a burst of year end productivity, Blender 2.55 was released to the general public with 400+ bug fixes last night. Two hours later, Blender 2.56 was released with at least one new bug fix.
I'm not sure what the issue was that cause the second release, but I'm glad to see them jump on it. It makes me happy when tool makers care about their product. Cheers to them for the quick turn around.
They have been changing around a lot of the underlining API for Blender recently. If you have older Blender projects around, you might test them out in the new versions before dumping your older version.
Also it looks like a 2.56a might be on the way soon due to a bug in the cloth sim stuff. If you aren't using it for that sort of work, you probably are fine.