A while ago I was considering Panda3d, mostly because Soya3d refused to work on my system at the time. I discovered that Panda3d was a typical, gigantic, terribly over- and mis-designed framework, but of all frameworks that have these traits, it is the only one that had a (seemingly) complete Python interface with a real game written entirely in Python making use of it. That excited me, so I put some time into figuring it out.
Well, long story short, Panda3d quickly crushed my soul with its horrible installation process and its bad support on Linux, and I got bored with the whole idea of 3d engines for another few months. With the release of Soya3d 0.7, however, it no longer crashes on my system -- and in a few days of playing around, I am elbows-deep in really fun 3d stuff (as opposed to knee-deep in a pile of installation and deployment rubble).
The fact that Soya3d is GPL saddens me, but I don't actually have a specific need to put my software that uses it under a different license - and if I ever do, I figure I can put the core game itself under the GPL and have it load non-GPL plugins and data, a la the Linux kernel.
The best thing about Soya3d is that it's written 100% *for Python*. It's very easy to install, as is most other Python-based software, and the API is really easy to use. It doesn't have great API docs (although it has rather good examples) and is lacking some features like cell shading and shadows, but the Pythonicness totally dwarves these negatives.