Comment 1 for bug 474637

Fedora contributed some awesome stuff towards tooltips in GTK+, which (if I understand correctly) have landed upstream and will be upon us with 2.30 / 3.0 (whichever it is). Those contributions will change the scene quite significantly :)

Info over here:
http://blogs.gnome.org/mccann/2009/11/01/just-leave-it-on-the-counter/