Thanks very much for all your Debian links.
I'll write here the answer to my question, as soon as I find it.
I am worried that the swich to Gnome 3 (and gtk 3) will make disappear most of needed applets (checkgmail, parcellite, dropbox, some Wine programs) even if probably current ones like Shutter, Network Manager and Sound will probably have a new version 3. Some old GTK2 programs important for me (like Notecase
which holds all my notes, the apwal
launcher, maybe trayer
and very probably others) will also not work anymore.
Very probably, overtime, all these missing things will be corrected, but I expect some months trouble due to these kinds of problems.
Will gnome-panel fallback
look like fruit cake without fruit?