They've implemented a GearScoring system into Cataclysm and are now assigning a number that they show when you try to queue up for a dungeon you aren't GearScored for.
http://a.imageshack.us/img838/5589/w...2110002631.jpg
Obviously, they don't/won't/can't call it GearScore, but essentially the concept is the same. Interestly, it counts any gear you have ever owned. The idea is to prevent people from trying to cheese the system and make themselves ineligible for tougher random dungeons (then switch to their real gear once inside). So your highest ever GearScore is recorded internally and used by the system to place you into appropriate dungeons.
This scoring system is in place on live, but they never showed you the actual internal number before (which appears to be nothing more than an average ILVL versus the GearScore addon which uses a weighted ILVL added up for each slot).