Others having problems today, too. Me:
Game has disappeared from my computer. Not listed in program files on any drive. Have the same prob as others with lock on "preparing to launch.
Tried to get into Steam Support and Forums. They will not load when I click on them. Like they are "dead."
When I re-load the DVD I get a message to reinstall or uninstall Skyrim. I clicked reinstall, and get to a "validating Steam files" bar. It fills saying that the "filed successfully validated. Then a pop up saying that Skyrim was successfully downloaded.
Still can't start game.
Suggestions???? Am really frustrated. Love the game.
Edit: No mods. New ASUS P5 motherboard (one month)
RAM 4 GB
NVIDIA 9300 GE Latest drivers
Intel Core 2 Quad Q 8200 2.33 GHz
Game played great for 86 hours until today.

//

Same here

Anhur: when you are saying "Same here" do you mean that your Skyrim game files are no longer on your hard drive?

Same here. Skyrim refuses to start after the Steam client update this morning. The preparing to launch Skyrim screen just hangs, and when trying to close Steam it hands in the "Finishing Cloud sync" screen.

The update seems to have broken Skyrim.

Try going into "Offline Mode" in Steam:

http://www.gamesas.com/topic/1328494-stuck-on-loading-screen/

Thanks to people on another post who noted that we can put Steam in Offline mode and still play. I was under the impression that one had to be ONline to just play the game. Now, I am a little happier again. So, others who read: I went to Steam and the 2nd item down is Go to offline mode. The Steam "config" or something of their cloud just went on and on and never ended. I just clicked out of Steam and then was able play the game.

Oops yeah, i guess that was a bit vague

What i mean is: I started the game, didn't work, tried to reinstall but couldn't start after the reinstall. But right now I can't even get on to steam so that must be the cause.

Anhur, check my new update post re going Offline with Steam. That seemed to fix the problem of at least playing.

yep, that did it. Thanks for the help

In case the offline mode doesn't work for someone (didn't for me). This fix did work, from the Steam forum:

Originally Posted by XtremeZ http://forums.steampowered.com/forums/showthread.php?t=2459703&page=21

FIXED it with

uncheck steam cloud sync
close steam
rename appcache to appcache.bak
reboot steam uncheck steam cloud sync in settings again

PLAY GAMES!!

Can't start Skyrim but Dungeon Siege III starts. I hate steam.
EDIT: Got Skyrim workin in offline mode.

this is godamn irritating, wtf is wrong