We were told by a very frequent international traveler we ran into in Berlin that this was supposed to start being enforced May 1st and that it was particularly important for international travel. I don't know about "particularly important", but for domestic travel I can use either my passport (which includes my middle name) or my driver's license (which doesn't) so it isn't as much of an issue. Because I had already purchased two international tickets and on one I had a tight connection at LHR so I didn't want additional delays, I called AA to get my name changed on my tickets to include my middle name. They were unable to do this on the flight that included a leg on British Air. The AA rep told me that it was my fault for not using my middle name when I purchased the tickets. When I pointed out that the online booking form only has spaces labeled "First Name" and "Last Name", I was told that when I filled it out to buy my tickets I was supposed to have put my middle name immediately following my first name in the space labeled "First Name". I suggested that AA might consider revising the on-line form.