Mojang login and session servers are having stability issues today (and have been since early this morning). As a result, you will likely not be able to log in to Minecraft or connect to servers until the issues are resolved. Since both the login and session servers are flickering on and off, you MIGHT be able to get in if you're extremely lucky, but don't count on it. This is NOT an issue with Alice, or something sk can fix. Mojang knows about the issues and is allegedly working to fix it. If you want to know when Mojang fixes it: http://xpaw.ru/mcstatus/ In the mean time, you can play in offline mode in single player, but you won't be able to play online until Mojang fixes their servers.
I agree, 100%. Ideally, they'd have logon and session servers world wide and set the game to use the closest one... but then they'd have to make the servers talk to each other to sync up session data... it'd take some work, but it's doable. They just need to suck it up and do it.
Because Mojang hosts their stuff on-site so that they can do whatever. If they had a backup server on-site as well, then it would probably fall when the main one does.
False... The Logon and Session servers are hosted on Amazon AWS (US-EAST-1: N. Virginia) region. A simple traceroute would have told you that hsun... tisk tisk.