Cataclysm: Heroic Shadowfang Keep and Deadmines Available at Launch: "I know you all heard the bad news that heroic modes for and wouldn't make it in for the launch of Cataclysm. Thankfully, it seems the original appraisal was wrong! Valnoth has come along and posted an announcement stating they will have the heroic modes for both SFK and DM at launch!
Heroics are not ready for testing.
Heroic Shadowfang Keep and Heroic Deadmines WILL be released with Cataclysm. You will not have to wait for a later patch.