Based on what happened during Blaster, it might be a good idea to hit Windows Update tonight to get the latest patch, MS03-039, which addresses another RPC vulnerability. To the best of my knowledge there’s no worm that exploits this vulnerability, but based on sad experience it’s only a matter of time. As a bonus, this patch supersedes the one that fixed the vulnerability that Blaster exploited, so if you never got around to patching your system last time this one will cover you.
If WU is overloaded, you can also get the download for your operating system from the TechNet advisory. Background information for the less technically inclined here.