> I actually do use desktop calendaring software which
> will stop working this summer.
Which software is that? If it's currently working with Gmail's CalDAV support, then it ought to continue working into the future. Google is not dropping support for CalDAV. > I communicate with people via XMPP who are not on Talk.
This also ought to continue working. Talk is still based on XMPP, and server federation is still working.If Google actually does shut down support for either of these open protocols, feel free to object as much as possible. I'll be right there beside you. But right now you're jumping from "Google might possibly drop support at some indeterminate point in the future" to "Google will definitely drop support in a month", which is not supported by evidence.