I'm loving the changes. The Heroic Blackrock Caverns movie looked pretty promising.
I do feel there's going to be loads of RAAAGGEEE because isntances won't be an uber easy emblem grindfest anymore.
Tho I think that making instances harder when you actually outgear it would be nice too (atleast for heroics). Tho I guess you then get problems when you have like 2 people who outgear it massively and a tank for example who barely has good enough gear.
But I certainly like the changes in CC (and my lock who'll be king of CC with glyphed fear). And it seems they're trying to make boss encounters a lot harder again.
All in all I'm looking forward to Cataclysm with the talent changes, the need of CC and the whole guild revamp. The only thing I'm not sure about are the stats. It seems they're dumping the stats we have to use now in well .. less stats that combine a few of the ones we have now. Which could lead to every caster or every healer and perhaps even every caster and healer needing the same kind of gear etc. But I'm not in the PTR or beta or anything so I could be wrong.