I'm not a dev, but if is true of what they say, "that Molehill will be similar to Opengl ES 2.X", then 5th version of "Opengl Superbible" should be pretty good if you want to learn how Opengl deals with shaders and low level stuff. Maybe the devs can weight in to see if I'm right.
If you want to learn more about 3d concepts in general then "3d Math Primer for Graphics and Game Development" is what you want.
