Every Gtk release deprecates a lot of stuff, those guys can never seem to
decide on anything.
To be fair, we do kind of the same [ Not sure how we compare in terms of
number of years between declaring something obsolete and actually
removing it, tho. ]
At least for things we deprecate, I don't expect everyone to immediately
start using the new functionality, because many Elisp packages want to
provide compatibility with older releases, so I think it's OK for Emacs
to use deprecated Emacs interfaces as long as they've been
deprecated recently.
But we should update the code to use the new replacement "as soon as
possible" within the limits of our manpower and the added complexity of
potentially having to support both the old and the new functionality at
the same time (via configure tests, typically).
I don't know if these should be fixed in emacs-24 or not.
No, much too late for that.
Emacs 24 probably won't compile on Gnome 4, but chances are we have a bugfix
release out before Gnome 4, or even 25.1.
If/when this is a problem, we can indeed release a bug-fix for it.
Stefan