Per the Internet Storm Center:
We have received a couple of inquiries regarding the unavailablity of Comcast. Apparently Comcast is experiencing problems nationwide due to an equipment update. This does not appear to have any connection to the DNS Cache Poisoning that we have been following over the last few days. The Comcast technical problems should be resolved shortly and all will return to normal.
Right… like I believe that their technical problems are going to be resolved any time in the next century. I've met one or two people on the inside who have been helpful, but… Time Warner spoiled me. If I could switch to DSL here, I would. Given that we missed our entire live broadcast tonight due to Comcast issues, we may have little other choice than to have ISDN as a backup (or fork over big bucks for a T1 – overkill).