Latest developments on python on guile is to make python's generator deep copyable. This means copying delimited continuations and I'm happy to acknowledge to a certain degree this works. Both pcomming 3.0 works as well as current stable 2.4. There is a problem and that is it assumes no data is put on the stack in raw format. Python's implementation is to set variables with set! so I expect it to work for python programs. However scheme code can store stack elements in raw data and hence that optimizartion needs to be turmed off to be sure. Also if one want to serialize continuations currently this does not work with the jit function and more work must be done to assure that it works together with the jit engine.
Note: deep copying of generators is not suported by cpython see http://c-lambda.se/deep-copy.html for an example Happy hacking