First time poster here as well.
Our unit still plays ArmA2 as well, partly because it's not all too different from ArmA3, but mostly because of all the modded content that is still in ArmA2. I guess that once more and more mods are ported to the third instalment, it will slowly take over the role of ArmA2. I mean, hardly anyone plays the original ArmA these days, right?