The best place to sort this out is probably
http://freedesktop.org/ That is where GNOME & KDE agree on
interoperability issues.
gstreamer seems to be one candidate.
If you can get GNOME & KDE to agree I'm pretty
sure the
distros would follow. It's just a matter of coming up with
a good solution.
If both choose any solution then there are still other
desktops which will not follow...
(And remember GNOME & KDE are multi-platform - so
I don't
think GNOME & KDE apps can use ALSA directly.)
...and that's why there will be no common solution.
Best regards
ce