Arena in WoW Cataclysm

As for the arena Blizzard didn't say much, there will be some new arenas in WoW Cataclysm but things will remain just as they were.

This is their statement:

"We're pretty happy with the arena system where it is right now. There's a huge number of people using it. We're seeing less than we did in BC because in BC a lot of people viewed it as a free way to get the best gear they could possibly get."