could be fun for senarios and snapshots, but i can see them being overly used in the MA. Where field captures would be impossible. Then again dropping some eggs or rockets to "disarm" them would make it possible i guess. Would be cool to lay them down on a stretch to town to limit the movement of GVs. Or even stop spawn campers!!
In that case, ha, another idea, when they are laid down, a friendly ICON comes up where they have been dropped so you dont "accidentally" drive over a mine field.....