Not sure where you are with Twisted or how long you've been using it so I apologize if this is 10 steps ahead...
We haven't open sourced any of our work yet... But...
We made our own Web.Request object that works with Deferred's properly (instead of NOT_DONE_YET).
We made a new PbClient interface and PbServer interface that supports multiple 'applications' being loaded separately at different times. We'd like to polish it a bit before we release the source.
The client component supports robust connections... (if you restart the server, the client objects are automatically re-connected to and restored) Normally Twisted just throws StaleBroker and your program Bombs...
We did an integration with PyBonjour so Perspective Broker locates servers using Zero-Configuration-Networking.
And the list goes on...
Shoot me an email if you're interested in talking code sometime.