Yep, it's not the little things that concern me about an EMP, it is the wholesale loss of electicity in just about any form once the batteries are gone. Alternators and generators will be rendered inoperative, so will anything with a piezo device in it. Relatively speaking, though, I am not too concerned these days about the chance of an EMP being lit off.

As for terrorists, it would be of far greater impact for them to detonate a dirty nuke in a metro area than to try and generate an EMP. Most tactical nukes, such as what they would likely get their hands on, won't be able to generate an EMP big enough to effect an entire region, let alone the whole country. Now if they could set off a bomb in the right location to allow the cloud to drift over a large enough area, that would fubar us pretty bad I think.

I fully expect that the next solar cycle peak will impact us quite severely. The sun is already overheating the solar system now, and the amount of radiation it is kicking out should reach some of the highest levels ever recorded. It would not surprise me at all if we take a direct hit from a major flare in the next decade and lose a lot of the birds we've put up, such as our GPS, our weather sats, our broadband telecoms. We could see the first 150+ Mhz persistent skip zone in recorded history.

And you thought your cellphone coverage was bad now!