Created attachment 70694 [details]
/usr/bin/gnome-wm with Compiz support

don't you need to start the gnome-window-decorator as well?

For complete functionality you do.
I have it as a session task which is launched during session restoration.

Created attachment 70801 [details] [review]
gnome-session-2.15.90-window-manager.patch

So the above is what we've ended up using in rawhide.

Created attachment 70870 [details] [review]
gnome-session-2.15.91-window-manager.patch

Update to work with 2.15.91

One problem Novell ran into with something like that patch is that if you use
the Fast User-Switch Applet to do an Xnest login, you have to run metacity, not
compiz in the nested login, since Xnest isn't Xgl. (I assume this is a problem
when using aiglx too.)

Our current patch makes gnome-wm pick between compiz and metacity based on what
X server gnome-wm is being launched under. (But our test for "what X server is
running" is a bad one, and doesn't deal with aiglx anyway, where some users
may want to run metacity and others compiz.)

So we don't actually support fast user switching in Fedora /RHEL (because of all the complications that come from not wanting to share access to vpns, device ownership problems, etc), but could you just key off of whether GDM_PARENT_DISPLAY is set?

There's also bug #334210, a proposal to remove gnome-wm.

I committed an updated gnome-wm version.
Ray, I suggest you add a script in /etc/X11/Xsession.d/ to define WINDOW_MANAGER if the gconf key is set.

isn't it called gtk-window-decorator instead of gnome-window-decorator these days?