could also be flakiness on the nodes as well. Recent weather issues... oversold markets... could even be bad hardware injecting feedback/noise on the line down the street that knocks people off intermittently.

Can speculate all day I guess. It doesn't seem to be massively widespread yet--very likely it's regional. So it may actually be something between you guys and SE having issues, just no one has managed to identify just what it is yet. We once suffered similar issues for 2 days before TWC finally tracked down a bad amp around the corner that was wreaking havoc on a local company's webserver's line. Might need to push through for T3 support from your ISP to investigate line quality not just on your line, but possibly your neighborhood.