But that's not what this suggestion is about.
Many people run dual screens, which is not good for streching the HUD across - who wants to have their crosshairs right at the bevel between screens. Yet, there is still some potential great value in providing dual monitor support. Here's what I'd love to see:
Primary screen - unchanged from today's game. 2nd screen would contain a full sized map with all active details you see in the mini-map & beyond. Alerts you see on your main screen might have additional information on the 2nd screen - ie, the location of incoming missles. Around the map would be a mech image for each of your teammates mechs, including their current health, weapon loadout, and status of each part of the mech. Ie, the same image that you see when you target an enemy mech, that appears in the top-right of your HUD - show this same graphic for all teammates on the 2nd screen so you have realtime information about the state of your team, and can understand important things like their weapons loadouts, so you can better assess who to work with, who may need additional cover/support, or who is a good mech to hide behind

Items like ECM could still have a negative affect on the 2nd screen - if an enemy with ECM in disrupt mode is too close, you loose the info on the 2nd screen, just like you would on your mini-map on your main screen.
I'm sure more detail could be fleshed out, but this would be the general concept for a 2nd screen in MWO.
Lokatana.