@HideoK - Im almost certain I will have the plat for MW2 for this Tuesday. I only need to beat only one more mission on Spec Ops and it isnt the juggernaut ones.
There is a way to work around the juggernauts with 2 players. When one player dies, if he stays on stairs for example, the juggernaut wont move. So the other one wiill have an easier time to take him out. Specially if you are under the stairs. Or you can keep reviving the other player till he kills the juggernaut.
It takes a while, but it works.