By the way, libjingle, the Open Source library for writing jingle applications, already mostly speaks XEP-166 and XEP-167. We're still working on XEP-176, though. http://code.google.com/p/libjingle
I have a nifty idea for a small project which would make use of libjingle, and I'm about ready to go buy a camera for my desktop to work on it. Is libjingle to the point where I could interact with my Google Talk contacts in their browsers? My other option is libpurple and their implementation and I am not very excited about that prospect :)
By the way, libjingle, the Open Source library for writing jingle applications, already mostly speaks XEP-166 and XEP-167. We're still working on XEP-176, though. http://code.google.com/p/libjingle