Last year we chalked libjingle as our choice for a XMPP library, since it handled all the networking we needed (ICE-UDP, HTTP, etc) tightly integrated with XMPP through a standard protocol.
On closer inspection, we found why libjingle hasn't really been adopted by the community yet. For starters it requires patches to build the latest release with GCC 4, and no release has been made to include these patches in months. Not a good sign.
Next we find there are no dynamic libjingle libraries, it builds as static only, and doesn't build for C programs (only C++). Unless we transformed our project to build as C++ this isn't an immediate option.
Looking over the libjingle code structure, it's in a severe state of poor maintenance. The internal name for it appears to be "libcricket", with naming confusion all over the place, code format inconsistencies, and extremely poorly documented.
Thus, libjingle integration is unlikely until after PySoy's Beta-3 release when we'll have time to write the C shim code as a dynamic library.
All this said, libjingle appears to have great potential for us and the entire free software community, it's just in need of attention from a few detail-oriented developers.