Any battle tech that's an order-of-magnitude cheaper to kill than to produce is destined for obsolescence. You can see this happening now with main battle tanks, which are easily knocked out by IEDs and increasingly sophisticated man-portable missiles. It will be interesting to see what happens to the manned air superiority fighter over the next couple of decades now that unmanned drones are being deployed on a wide scale.
Few M1s have been destroyed or badly damaged by insurgents in Iraq. Their use has declined since the invasion not because they are too vulnerable, but because they are less useful without enemy tanks to engage and using them against infantry in urban environments risks heavy civilian casualties.
I was thinking less about the conflict in Iraq than the conflict in and around Israel, where small groups of insurgents have over the past decade mounted increasingly sophisticated attacks on Israeli armor in the open. The deterrent factor here is just as important as the ability to blow stuff up.
Probably nothing. Remember that unmanned drones were used in combat in Vietnam. They were quite short ranged of course, and could only be used for one mission: Sidewinders.
