The second release candidate of Blender 2.71 is not out. You can get it at Blender.org.
The release notes are linked to from the main page.
Thre is an update that allows Blender to handle normals in such a way that creases and sharp edges can be made without having to duplicate geometry. As I understand Blender had used double vertices along creases to create hard edges. I don’t know if changing that will follow through to Second Life™ and give us few less vertices to deal with. I’ll have to examine the Collada files to see if I can tell.
Dyntopo now has constant detail… this is for those sculpting models. I think the idea is a setting will control the polygon density when constant detail is enabled.
How color is rendered in Painting mode has changed. I gather that we will see a better representation of color… and there is a color wheel out where it should be more usable.
Plus the tool gets new icons for the ‘brushes’.
It looks to me like the release notes are incomplete. As this is an RC that is to be expected.
There is nothing here that is earth shaking for those building for Second Life. However, 2.71 does have the ability to bake textures using Cycles and Nodes.
I haven’t tried it with AvaStar, yet. I’m working on a sofa and trying to learn more about texturing, so it may be a while before I take the time.