Peter Jackson will be filming The Hobbit for 3D, and he will be doing it with the brand new RED EPIC camera, the successor to the successful RED One digital camera. The EPIC will have a “5k” resolution, which means the horizontal resolution will exceed 5,000 pixels (the EPIC is reportedly 5120×2700). By comparison, “1080p” for your standard HD TV is 1920×1080. This allows for better theater projection resolutions and also allows for limited digital zooming to reframe shots without re-shoots.
The size of the EPIC makes it far more practical for 3D filming, where they have to mount two cameras together to get the stereoscopic view. Dual mounted Panavision cameras are quite heavy and bulky.