A slowdown over the weekend on boards generally is something I've noticed too, tho not just in the last few weeks. It seemed to start shortly after the events of Sept 11 when people suddenly realised there was more to life than work and that spending time with family and friends should be a priority.
Have to say tho, that this phenomenon is far less apparent on Oprano than on most other boards. This is one of the few boards that still seems to maintain a reasonable level of activity most weekends, and on some weekends (depending on the topics under discussion), Oprano still flies.