I'm in Doggles camp to be honest.
Are you guys really convinced the error is in the Steamworks platform which is used by about 150! games since it's release in 2008 and only CLOD magically suffers from it?
To my understanding is just a protocol which needs to be coded into the game..if it's done right everything works, if there is an error somewhere in the gamecode you get bugs like this server problem.
Could compare it to your gmail timing out or being inacessible due to a faulty switch on your ISP's side. You can blame Google all you want and demand they fix it but until your ISP get's their stuff sorted nothing will change no matter how hard you shout.
http://steampowered.com/steamworks/gameservices.php