I have three monitors set up at present and thats cool too. They are all old resolution 4/3 aspect but I can now spread the project over two screens and get the MIxer on a third to the right.
I have been running dual screens for a while now in 19 in - about a decade.
I may well do something similar with the new big screen - one big one and two satelaitesw either side. See how things go.