This was a lot simpler than I expected: I just used py2app and it worked fine (so far). *drool*
Edit: I got happy too soon, but it's a step in the right direction. I don't think it's including everything since it appears to use the software renderer (fps sucks, no texture filtering) and the map was totally black, though particles were showing. If anyone else is attempting this (I have a feeling that sound I hear is a giant whoosh of being on my own) I'd like to collaborate to get this working.
(rant)
This is a really nice engine, but it's _far_ too difficult to build. This is the second day of solid effort, and I still don't have all the components built (cal3d, ode says it's too old, libjpeg can't be found, sound test crashes, etc). There would be a lot more activity around this engine if it was made more user friendly. More contributors, more donations.

Even supplying prebuilt binaries of dependencies for each platform would go a long way. Assuming that getting the engine built is 90% of the reasons people are not using CS (my guess based on my frustrations while trying), I'm surprised the devs don't do this already. Why are there no cal3d and ode prebuilts, for instance? I know they're "optional", but anyone seriously wanting to use the engine will need them so in practical terms they are not optional.
No offense intended to the hard-working devs who have done an incredible job, but I'm very disappointed because this engine looks really powerful but I (and many others, I feel) can't use it because I can't get the engine fully built and working.
(/rant)