Sheldon is moving from Comics.com aka dilbert.com to their own independent site. Seems that comics.com obliterated Dave's notice of the move on their site to the public.
If you like the strip, you will love what's happening now that Dave is sponsering his strip. Large format daily strips. The entire archive available online. More reliable daily updates (comics.com had a tendancy to skip one every once in a while - although they would catch up a few days later.)
Here's his announcement on his blog: http://sheldoncomics.com/archive/061106.html