There was some confusion when it first reappeared on the slate if the original hand-drawn Disney project Frozen had, like Tangled before it, morphed from cell animation to pixel animation. Turns out it’s been brought thoroughly into the new age, and when the 3D film wows your kids on November 27th, 2013, it will assuredly be in familiar CG animation.
Not much else to it for now, though you can hit that link above to learn a bit more about the project.
About the Snow Queen (from Wiki)…
The Snow Queen, queen of the snowflakes or “snow bees”, travels throughout the world with the snow. Her palace and gardens are in the lands of permafrost, specifically Spitsbergen. She is successful in abducting Kai after he has fallen victim to the splinters of the troll-mirror. She promises to free Kai if he can spell “eternity” with the pieces of ice in her palace.
Source | Disney