An initial version of the new xinerama support is committed into hg, it's not finished/polished yet, but the basics are usable already. During the development I decided to have a bar per monitor, instead of just one bar. It's less confusing that way.
Monitors are currently selected through pressing Mod1-w, Mod1-e (just two initial keybindings), and clients are assigned to the selected monitor and can be re-assigned using Mod1-Shift-w, Mod1-Shift-e resp. There are several bugs still, esp. related to the floating handling (it's currently possible to have a floating client assigned to a monitor even if it's shown on a totally different monitor). The code will have a lot of polishing and some config.h options will go away possibly... one candidate is topbar. Bug reports welcome. Please don't do code reviews yet, I know that it's ugly and needs polishing. Kind regards, Anselm