I know there's probably one or two people out there who would like to see another entry in the OpenGL ES from the Ground Up series.
The good news is, I started one a while back, right after WWDC. It's a fairly extensive introduction to OpenGL ES 2.0 and shaders.
The bad news is, I have no idea when I'll have time to finish it. I'm behind on writing the next book, plus I'm frantically trying to get ready for the iPhone Boot Camp NYC this weekend (boy, that snuck up on me). I will finish it at some point, though.