Dang you shoe bomber - though they were already making you remove shoes everywhere I went well before that. It used to be some shoes on a TSA judgment call, but then became all shoes as time went on (same time as the 3oz rule, I guess).
Someone could make a MINT off of TSA-approved shoes (like the TSA-approved laptop sleeves). Every time I try to go through in my Five Fingers I ask them what I could hide in 2mm of rubber that they wouldn't catch in the scan (either kind), and they give me the "them's the rules!" face. I'm sure the problem is "where do you draw the line?" and that in the end it's faster to push people through with one rule than to actually think "you could hide stuff we couldn't pick up on the scan in those shoes." I don't really mind the backscatter machines but I prioritise traveling expediently over being in a giant crowd of people with ruffled feathers. Not having to take off my shoes is even more expedient, even if they like to look at my hobbit shoes in the baggage scanner.
I was able to wear my five fingers through airport security in Amsterdam, Rome, and customs arrival in Seattle (where you transfer back to the airport for domestic flights). Apparently my shod feet are safe internationally, but not in the states. ;)
I am concerned about the health issues, it makes sense that there would be a class of people who should avoid exposure. We accept a certain amount of risk in everything we do, the key is to be informed.

