I can't wait to PVP in Cataclysm particularly as Disc. I already play offensively with mana burns, smites, holy fires etc... In Cataclysm it will only be better.
2s with a Mage should be incredible. Currently, you have to play very offensive with a mage in 2s to be effective and with the new talents "Pentitence", "Evangelism", and "Archangel" a disc priest can be a wrecking ball. This isn't even considering "Time Warp". I'm thinking something around 65-11-0. http://www.wowtal.com/#k=v1NwstkB-97w1.9dw.priest A very offensive/defensive utility build. Priest is already and will continue to be the best offensive healer.
just very excited!!!