VAC2 is now in it's public beta and Valve is pushing for admins to update their servers to prepare for release. I havent heard about it actually logging or banning yet, but it would be safe to take the necessary precautions.
http://www.counter-hack.net
http://www.csnation.net
http://forums.steampowered.com/forums/showthread.php?s=&threadid=288810