It's true--I have succumbed to the same mysterious affliction that my husband and son have, though so far, I am under control. That's what we always say in the beginning, right? :) They have used multiple monitors for a long time now, and the upside is you can work on several things at once, without having to go back and forth between open windows or resize your windows in order to see two things on the screen at once.
You start out just getting a bigger monitor, then at some point, you want two bigger monitors. I think I can stop here, but already since the guys set this up last night, I'm feeling my productivity increase! Makes me want to get to work.