I have been playing with Pyglet, and I am very happy with it. it's still in alpha, but is developing fast and the alpha is already very stable.
The most important feature of Pyglet is that it's being designed from the ground up to be OS independent (Linux, Win, OSX) without external dependencies. For that, it uses the standard OpenGL implementation of each of these platforms via ctypes. This makes it my last best hope for a multi-platform graphical interface kit.
It already has a growing widget library, support for layout of html documents, import 3d models created with wings3d, a scene 2d module with support to sprites and collision detection, and a lot more. Most of these functionalities are available only in the SVN version. The (stable) release is somewhat more limited.
Go check it out! it is (IMHO) one of the few truly exciting graphical libraries in the python scene.