I played one in 2 of the beta events and I gotta say that you can do whatever you want with your elementalist just more effectively if you trait certain ways.
Elementalist seems like one of the most active classes to me. Not as far as mobility, though they aren't bad there either. But when I watch pvp vids, skilled players are constantly switching between their attunements. And casting while moving pretty much guarantees that no matter what you're playing it isn't going to feel like wow.
Just my 2 cents.