The new patch made it very easy to span Black Shark across dual monitors. Alls you have to do is go into your options.lua file and edit your height, width and resolution settings to whatever the total resolution is to whatever you want.
For example I have 2x 1980x1200 monitors, in the options.lua file my "height" setting is at 1200, and the "width" setting is at 3840, the resolution option is set to match that at "3840x1200." Alls that is left to do is edit your 1Camera.lua file so that the width and height match up to whatever your resolution is, also make sure to adjust your aspect ratio to match.
You will find that running dual monitors has disadvantages though. The aspect ratio isn't very great (you will have to look down in order to see the ABRIS/Shkval), the Helmet mounted side and hud are both in the very center of the split between screens, making it hard to properly fly the aircraft.
It LOOKS very cool though :D
What would probably be best to do though, is manage to squeeze the ABRIS/Shkval screens onto 1/3 or 1/4 of one monitor, and run it like that. I am in the process of configuring DCS to do just that, but haven't had much luck. I saw a ss of a guy who had DCS configured to do that, but he didn't post any config files :(
SS of what I'm talking about: http://img443.imageshack.us/i/20090711122455.jpg/
What happens is that I can get 80% of the way there. I can get both the ABRIS and Shkval to show up in an area to the side that I have setup for them, but they appear on top of each other in the top left of my monitor. I can move them up by giving them a - value in the 'x =' option in the .lua, so you would think that if I give them a + value it would move it down? Nope, as soon as you assign a + value to either one, the configuration doesn't detect the configuration for either ABRIS or Shkval. wtf?