WARNING: This is completely unsupported. It could completely break your system, and you will probably not get any help from Debian voulenteers or the Debian GNOME maintainers. I do not take any responsibility from any issues or data loss caused by this procedure. PROCEED AT YOUR OWN RISK.
DO NOT report GNOME3 bugs after having used this procedure until after you have reverted back to the official install with pulseaudio, and verified that the issue remains.
Note: I have on purpose assumed a certain level of knowledge in the instructions below. If you can't understand them, then you shouldn't be doing this.
The first step is to get a replacement pulseaudio package. This is because
the GNOME packages depend upon the pulsaudio package, and won't let you have it
installed unless a pulseaudio package is present. You can create it with
the tools found in the equivs-package. For convenience I have uploaded
one, you can download it from
http://zarb.org/~zerodogg/pulseaudio_2.0_all.deb
(it is signed with
my gpg key).
After that package has been installed, you're essentially pulseaudio-free
(after you kill any existing pulseaudio-processes, which you should do now). To
get a volume control back in GNOME, install the volumeicon-alsa-package. Then
install the Evil Status Icon
Forever
GNOME-extension. Now edit
~/.local/share/gnome-shell/extensions/EvilStatusIconForever@bone.twbbs.org.tw/extension.js
adding 'volumeicon' to the notification-array. Finally, log out and then
back in (or start volumeicon, then restart gnome-shell). You should now have a
simple volume icon in the shell, and be running without pulseaudio.