For me it's really the first time to experience the step-by-step improvement of an beta-system till it's final steps to a release, and I can say that it is a really amazing thing. Though, I can just recommend not to do this on your main system or on one that has to be as reliable as possible (router, webserver etc.).
This said, the really strange thing for me about this beta-stage improvements is how some things get a top priority to be fixed and some don't and under those things aren't fixed you'll find some pretty basic stuff e.g. the volume-control in the notification area.
I can't really tell since when, but as a design decision the volume-control wasn't anylonger a freely placeable gnome-applet but appeared automatically in the notification-area, but since some update it's just gone and since you can't find it in the "Add Applet to Panel"-Dialogue the not-so-geeky-user has no volume-control-applet anymore. The weird thing is, that the fix is pretty easy and could have been a 1k or so update package, but till now it wasn't.
Till today I wasn't really looking for a fix and thought it's going to be there someday again, but now it annoyed me and I started looking how to fix this problem which turned out to be pretty damn easy:
Getting back the volume control applet:
First I had to find out, that the little program to control the volume is called "gnome-volume-control-applet". If you know this, you can just start it by typing gnome-volume-control-applet in a shell.
The rest of the fix may appear to you allready: Go to Preferences/Startup Applications (formerly Preferences/Session), click add, put a description of your choice in the name field, and gnome-volume-control-applet in the command field, hit OK.
Now you can restart the system and watch how it loads automatically ;)
It seems that the volume control is loading automatically again, but not into the notification area one might be used to on a gnome desktop. There is a new thing called "indicator applet" described as "An indicator of something that needs your attention on the desktop", the volume control is now displayed inside this new applet. Since I never really used the envelope symbol with all its options I decided to remove the whole indicator applet and used the workaround from above to get a volume control applet back.
Then something strange happened: I started rythmbox and when closing it (meaning not really closing but 'iconifying' it) it was completely gone, nothing at the notification area or else... but wait, I removed this new notification thing, maybe it's there? so just for fun I added it again and really, the rhythmbox icon was inside this new applet. So what's really going on here? Do we now have accept that there is a notification area for really important things concerning the system (the old one) and one for not that much important things (the new one)? Why? And if it is a design decision why not make it possible to switch it back the way people are used to, by e.g. re-adding a used-to volume-control-applet to the gnome-panel applet-list and/or make applications/the gnome-panel beeing aware of the possibility, that there is no "indicator applet" and the rather display icons in the notification area then not displaying them at all. I just hope this is going to be much more user friendly and less confusing in the final release end April. Just to make sure: I don't want to bash any design decision here or want to say "don't change anything people are used to", but if you change something like that with the possibility that one doesn't really find it a change to the better, you should at least give everybody an easy option to change it back. I'm actually giving it a chance right now, nevertheless I still don't need the envelope symbol functions, but I bet somewhere somehow this whole thing is configurable ;)