gst-plugins-good 0.10.2: gst_gconf_get_default_audio_sink(void)
gst-plugins-good 0.10.3: gst_gconf_get_default_audio_sink(int)

We can now not use this function. Luckily in Banshee I was still using the element factory to get a gconfaudiosink, but looking around at different players, I see that RhythmBox does use gst_gconf_get_default_audio_sink() in its GStreamer backend, so problems are to be expected:

http://cvs.gnome.org/viewcvs/rhythmbox/backends/gstreamer/rb-player-gst.c?rev=1.75&view=markup

As for the revision introducing the API/ABI breakage:
http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/ext/gconf/gconf.c?sortby=log&r1=1.5&r2=1.6&pathrev=RELEASE-0_10_3

Looks like a patch from Jürg Billeter <j@bitron.ch>.

API/ABI should not be broken. The introduction of the "profile" property on the element itself is fine, and much welcomed. Applications whishing to use it can query the element's class to see if the property exists, and set if it does.

An alternate function should have been introduced instead of breaking the existing one, something like gst_gconf_get_default_audio_sink_with_profile(int profile)