Snowman Eyonix posted an update to the ongoing Comcast issues on the forums today: he says that Blizzard is talking to Comcast about the problem, and that they may have identified the problem in a third-party network between the affected folks and Comcast themselves. He says work on the issue is ongoing, and that while they don't have an ETA, he'll let us know when there is more to know.
We don't know if the "third-party network" includes those Los Angeles datacenters that were being blamed earlier, and to be honest, we don't even know how widespread the problem actually is. A few of our writers are on Comcast -- most of us haven't had any problems at all, though one of our writers in LA is experiencing lag and the occasional disconnect.
We'll keep an eye on Eyonix's thread and let you know if anything changes. At this point, it seems the problems are known and Blizzard is doing what they can to solve things.