keep a close eye on the additions and corrections forum:
http://collectorsedition.org/forums/...isplay.php?f=4
if a new CE is announced someone will almost always post it there very quickly
if you're looking for stuff that has been already been released then just visit the database here:
http://collectorsedition.org/game-db
I would say between the database and the A&C forum you will know about 90% of the releases this generation.