Multi-monitor support is a long standing issue.
Here I'd like to ask everyone.
How should a muli-monior desktop bahave?
For the desktop panel:
1. one panel per monitor, configured separately
2. one panel exending to the external monitor
3. one panel staying on main monitor, no panel on the external one
4. one panel exending to the external monitor, but have the most
important panel applets on the main monitor, and the rest on the
external monitor
5. Other possibilities...
For the desktop icons manager, options are:
1. icons on main monitor only.
2. some icons on main monitor, others on the external monitors.
(Then how to handle icon rearrangement when the external monitor
is disconnected?)
3. others...
For wallpaper:
1. one wallpaper per monitor
2. one wallpaper extending to all monitors
3. others...