Hmm...I really like this. It's got wonderful motion, pretty awesome curves, and you've got a good base sketch here.
The motion itself is great, but what it's conveying is a little bit ambiguous. Her legs are saying trim lady, daintily walking throw a garden of wonderful flowers. Her top, however, is saying "I'm a wizard, and I'm going to BLOW YOUR FRIGGIN' HEAD OFF WITH MY FIREBALL, and stay cool as a cucumber." The combination of this looks like a beautifully clumsy girl flailing to catch her balance. While all of these are absolutely awesome, it would be a good idea to unify your piece so that if you cover her top up, you could still tell she is a virile wizard or whatever persona you want to create.
Your pretty awesome curves are definitely pretty awesome, but I think that her boobs, tummy, and arms are too broad. Just slim those down a bit, and maaaaybe add a couple pixels length to her legs, and you'll be well on your way to an ultimatum of artistic success.
Yes, a wonderful base sketch, much better than what I can do, but I think that it would be a very good idea not to sketch as though you're using a pencil. Take advantage of highlights and maybe another color for her shadows to really help form a solid base. It'll save you from the myriads of tears waiting to erupt when you have to put a brand new pixel over your beautiful sketch to make room for highlights and stuff.

Not an amazing edit by any standards, but maybe it'll help somehow!