I emailed someone at Maxis yesterday, they're no longer on the team that maintains Spore servers, but that team has been notified. Seems like they're doing some work now.
For Spore, the website is actually running directly on the same server used for the game's online features, so if one goes down, everything goes down. Yesterday they switched www.spore.com to point to a temporary server that just shows a maintenance page, instead of the currently-offline game server.
Unsure if this was planned maintenance or a glitch. Apparently there was some maintenance related to Spore and Sims 3 servers, so this might've been part of it, but not completely sure. If I hear back anything further from Maxis I will post it here.