It must have been down for a very minimal time coz between when I got off to let my brother play the Wii for a bit and now it seemed to function just fine with some obvious technical difficulties.
[You must be registered and logged in to see this link.]Matchmaking and LIVE are both up. The primary inhibition for now is with social stuff. Parties, invites, messages, notifications and functional friends lists. Those will be down for a while while they finish doing what ever the hell they've been doing to it today. In other words any thing to due with Forza should still work just fine. Game servers =/= XBLA
Edited: And for some odd reason... Minecraft saves are announced to be having difficulties. Can't imagine why. If you're going to play MC, disconnect your connection? XD