Sometime around noon EST a cut fiber on the Cox network has disabled all access to the Blizzard network, making it impossible for mid-eastern coast Cox subscribers to log into WoW. Normally internet protocols would reroute requests along another route, however, Cox seems to have their backbone configured to only route packets bound for Blizzard through this one route and it stops at ashbbrj02-as0.0.r2.as.cox.net (68.1.1.232).
So much for a leisurely afternoon of leveling my Paladin to 80.
[Update] Cox restored network access to Blizzard's data centers by 4:30 pm EST.