The Defense Industry has no shame when it comes to ripping off the taxpayer. Iron Dome may work fine on standard katusha rockets but Hamas will soon modify them to overcome the trajectory based computed intercept point. They will add a trajectory modifier of some kind (knuckleball, fluttering motion, speed brake with proximity fuse) which will make the intercepting missle miss. Another solution may be to change the payload of the katusha so that it is just as lethal after it is destroyed -- white hot phosphorus bomblets dropping to the ground.
from the article: Barak: Iron Dome missile defense system to be deployed next week