This morning it took 30 seconds to connect to EA servers, and multiplayer appears to be working. Still a bit long, but it's not 5 minutes. That's not unusual for first thing in the morning though, so I'll wait till tonight before I start to believe this might be solved.
RE: Achievements, it does sound like some people who can connect to the servers fine aren't getting theirs back. I know it syncs with the cloud, but if that's still not working you may still be able to use the console to unlock them offline, then go online and have the new data sync up correctly. It doesn't give you any multiplayer advantages (that I know of), so it shouldn't be bannable as cheating.
It seems that this problem has now been fixed.
Paul Guidera from iiNet over on whirlpool thinks he has solved the problem, and I just logged in with no trouble.
http://forums.whirlpool.net.au/forum-replies.cfm?t=2028035&p=6#r104
Happy gaming
