A few random thoughts. Three weeks ago, Congress gave Bush more authority to wiretap than he even asked for. Speculation is that there's chatter about an imminent hit on the US, and that would explain why Congress knuckled under so easily.
Second, it's hard to believe the US government would cut off the personal communications of its citizens in a time of emergency. It seems to me that someone would balance the advantages of cutting off terrorists' communications against the harm that will come to ordinary citizens if they cannot call for help or coordinate an evacuation with their families, and scratch that plan.
Finally, it seems like the Israelis are a lot smarter than us, and I don't know why we haven't taken some lessons from them. On the other hand, Olmert really botched the war against Lebanon last summer, so maybe Israel suffers from the same dumb leader syndrome the US has.