I just released new version of mining proxy, version 0.5.0. Older versions still works nicely, this adds some few features:

* Implemented method client.reconnect(host, port), so pool can now easily balance clients between backends or gracefully shutdown a backend without a miner outage.

* Added "--no-midstate" parameter. When used, proxy won't generate "midstate" field in the getwork response. Some old miners and Diablo still requires this field, but modern miners like poclbm/cgminer can generate midstate ourselves and in much faster way. So if you're using these miners and want to save a bit of CPU time, this argument is just for you. It speeds up getwork creation twice.

In the near future I'll publish complete API documentation of such commands like client.reconnect(), client.get_version() or mining.get_hashrate(). Stay tuned :-).