I think the reality of the matter is that until the war on Terrorism is complete, anyone travelling to the USA that enters into any port, can be sure of being given a close examination. Even as in this case, they want prior advance notice regarding aircrew.
I have also heard that passangers that want to submit to fingerprints, and other forms of biometric ID, will be able to pass through security with relative ease. This, I assume, is to speed up the entry and exit of people that travel very often. They can pass through security checks with minimum delay. Would this not be a good idea for aircrew? Then you would not have the worry about advance notice, security or immigration delays. Also, if you have nothing to hide, what are you worried about?