We're starting to get reports aplenty of the (North American) Rampage battlegroup having server outages at the moment, but the exact nature is... fuzzy, to say the least! The login server doesn't seem to be the usual culprit, since the problem is exclusive to Rampage thus far. Looking at the Tech Support forum, it doesn't look like Blizzard has given any updates on the situation beyond asking players to run a traceroute if they have the knowhow. If you're the sort that knows how to do something like that, please direct yourself to the official forums.
Hopefully this outage doesn't last too long, because we're going to be quickly approaching Saturday primetime. That's definitely not a good time for server outages! If anything major comes of this, we'll be sure to let you guys know. If you all want to help us on that front, just keep us updated in the comments below if you're one of the unfortunate Rampage players. If you're not sure what battlegroup you're a part of and seem to be having server problems, the server list is behind the cut below.
Update: The customer service forum has a far more useful thread. An investigation into the issues is ongoing. Thanks, siech0.