I am perfectly aware of the Jabber trademark situation, being a Jabber Council member. There is no problem in mentioning that your product is Jabber compliant, if you want to. The JSF has clear guidelines on what you can and cannot do with the mark, and when you actually need a license. You'll find that it is actually quite liberal.

That said, I don't suggest Google should state any relation with Jabber (the platform), but wanted to oppose what you said in the following quote:

Note that Google itself properly refers to the protocol as XMPP. You should too.

Let me close by thanking you for your kind words on our (JSF) efforts.