In addition to the animation support last post, I have just added limited pixel-perfect collision detection between arbitrary pyglet sprites. You can see the results in the video, right after the break.
The collision detection only handles un-scaled, un-rotated sprites for the moment, but does handle animation. It first performs a rectangle-rectangle check to ensure fast rejection of non-overlapping sprites, and then takes the intersection of the bounding rectangles to minimise pixels tested.
So far it seems to be reasonably fast, despite being implemented entirely in un-optimised python. The example shown below performs several collision checks per frame, and still runs at a handy 60 fps.