There is one change I am excited about in Cataclysm, in regards to Moonkin PvP. As of 3.3.5, as is made clear by my earlier posts, the state of Moonkin PvP is terrible, and it doesn't look as though Cataclysm will bring us up to par.
My one excitement rests with Starsurge and the Shooting Stars proc. Considering I keep my DoTs up nearly all the time in PvP, I imagine that Shooting Stars will proc frequently enough to keep my enemies on their toes. The reason I'm really excited about it is simple: it's instant. For the first time, Moonkins will have the possibility of having an instant nuke. Uninterruptible and powerful - two words that before Cataclysm could never have been used together when speaking of Moonkin PvP. For the first time, we may even have controlled burst.
And damage isn't just damage in PvP - it's pressure. If I am able to pressure my opponent in PvP, the balance tips in my favor. He is forced in the defensive, and I don't have to worry about keeping myself alive as much, which is one of our main problems in 3.3.5. It has been for so long too easy to put the pressure on us - but that was not just a result of our poor control and survivability. It was also because it was very difficult putting the pressure on them.
Shooting Stars is my Moonkin PvP silver lining.