Hey Mike! Comet for IIS is an area that doesn't seem to get explored
much. Sounds like an interesting project! How are you setting up the
server? Is your comet server running separately from IIS? You should
look at using CSP (Comet Session Protocol) if you haven't defined your
protocol already --
js.io has a working client-side implementation,
and there's various reference implementations for servers, e.g.
js.iofor nodejs or pycsp for python.
See http://orbited.org/blog/files/csp.html for the full specification.
Let us know how development goes!
Martin