I'll also throw my hat in for using C++11 where possible, for what it's worth.
I'd like to see some 3D getting in too - not for me, specifically, since I'm a sucker for rolling my own stuff, but because I have a sneaking suspicion that the user base of the library would grow significantly.
Support for more file formats would be great as well. Other than that, I don't really have anything specific to add.