Use paste.deploy to serve a twisted application
It is extremely unlikely that trying to do this is going to be worth the effort.  paster serve has it's own event loop, threadpool, etc. and Twisted apps expect something quite different.
You could try writing your own paster subcommand, but you're probably better off writing a .tac file that serves both apps for use with twistd.
I'm working on a project that has two parts:

A WSGI-enabled web app written with pylons and served with python-paste
A python-twisted application that has nothing to do with HTTP or WSGI.

I'd like to keep the configuration for both apps in the same configuration file. I'd also like to use paste serve to launch both the WSGI server and the twisted server. 
Is this possible? Can I configure paste to understand twisted .tac files?