On a dark and stormy night after repeatedly failing to record a tutorial successfully, I thought it might be fun to take the Sintel model off the DVD and port the materials for Cycles. And so it was :)
That's all I did, so understand that this model and all it's textures (see below) are licensed under Creative Commons CC BY 3.0 originally created by the Durian team working at the Blender Fountation for the Sintel Open Movie project.
The rig is a little wonky (missing most of it's controls) since it was created a while ago and the Blender API has changed a lot since then. I do plan to fix it up with the current Rigify, but not any time soon, so if you'd like to do that feel free.
Blender 2.65 doesn't have hair rendering support, so to get the hair to render in Cycles you'll need a recent build from either graphicall or the build bot, or simply 2.66 or later (once it comes out).
Now the textures for this model are a total of 260MB or so. Thus it's not included in this download and you need to download it separately from one of the links at the bottom. The textures are in a zip file, so to get it to work, simply make a folder anywhere you like, put the sintel_cycles.blend file in this folder and then create a folder in there called "textures" and unzip the textures.zip into that folder. So in your folder you should have the blend file and another folder called "textures" with all the images in there. It should look something like this: C:\anyfolder\sintel_cycles.blend C:\anyfolder\textures\someimages.jpg
Mirror 2 (thanks Marius Eckardt)