Dual screen and Unity launcher on 12.04

[Colin Law]

With the new dual screen launcher algorithm coming in Unity where I
believe the launcher either does or can appear on all screens, if I
ask the launcher to be permanently visible does that mean I am stuck
with a permanent launcher on all screens?  That would be really bad.
I have 12.04 but I can only use Unity 2d which is behind 3d in
development so cannot try it myself yet.

Colin