Well, today my home-based spam detection system failed. Starting yesterday (unknown to me) SpamAssassin, running on our home server, started tagging all incoming mail as "spam". Apparently there is a test in SpamAssassin to check for dates "grossly in the future" and the year 2010 is one of those dates.
As most things are, information on this bug is now available on the internet. My family now happy since the were missing a lot of "happy new year" emails!