I am logged into steam and have been since this morning, so no issues here. Might just be that I missed the whole issue with the server and got logged in on time. What I can't do is access my friends area, that's why I think I got logged in before the issues.
Steam Servers are currently in the process of being located to a different facility.
Approximately half of all accounts should now be functioning normally at this time. The remaining accounts will soon follow.
VALVe are working as quickly and as they can on this issue - there are obviously issues of resources/priority as basics such as essential services are taking priority in such a circumstance - as one would hope.
Actually I was just doing a search "somewhere" and found copies of Half-Life 2 (single player, no deathmatch) and CouterStrike: Source (can play on LAN and cracked servers) for download without the use of Steam.