Tulip coroutines[0] look rather good. As with C#'s async/await you have to propagate the "asyncness" to the event loop (using `yield from` with a future or another coroutine), which is not necessary in gevent, but that should be the extent of it.

[0] http://www.python.org/dev/peps/pep-3156/#coroutines-and-the-...