Thanks very much for the extensive post Dan. It would be great, for us, if you could keep us updated with what you discover about mobile 'XMPP', and what changes you need to make, because we'll undoubtedly need to look at it ourselves and wrap up and formalise the protocols (and who likes wasted effort? :))
As for the excitement - Android having XMPP onboard was/is a very exciting thing; the possibilities of what could be done with it embedded in a mobile core are limited only by the (somewhat warped) imaginations of the community in an open platform. /K