Its been intermittant, but all the posts I saw on US were people complaining about EU, because battle.net, WoW, Diablo, SC2, the lot were all down, including webpages. But the US stuff was working and people could post there, so all the complaints are about the EU servers. US was all ok.
But its definately beyond Blizzards control (for once), I spoke to one of the guys at my old company (who provide the internet access for BE) and they were having intermittant problems too. Seemed to be localized to Virgin and BE, but any other company that peered with either of those would be having problems too.