All of these posts talking about how terrifying/emotional/stressful the whole transatlantic pet experience is I could have written myself. I felt EXACTLY the same way about my two kitties (9-10 years old). I cried on the car ride up to the airport, and the kitties were meowing the entire car trip. I cried dropping them off at the cargo dropoff, even though as soon as the cats were out of the car and sitting on the floor they were calm. I cried sitting in my seat on the plane, waiting for the flight attendant to confirm that the cats had been loaded onto the flight, I cried for the 45 minutes we were stuck on the tarmac before taking off because there was fog and air traffic control delays, I cried for the first two hours of the flight because it was a REALLY turbulent flight with lots of bumps and such, and all I could think about were my little kitties hunkered down in the dark with all kinds of strange noises. I cried when we got to the pet reception place on the other side because I was afraid one "i" wouldn't be dotted or one "t" wouldn't be crossed and the whole reason I'd been separated from my husband would have all been for naught. And I cried when we loaded the kitties into the car, because they hadn't been meowing when they were sitting in the office while we signed the release paperwork but they started meowing as soon as they were in a moving car again.
I also cried on the car ride home, because my little Eliza peed her bed and the smell was really really awful, but that's kind of a different type of crying.
And I too was AMAZED how quickly my cats rebounded from the stress of the trip (heck, they rebounded faster than I did). I was reminded of Cesar Milan's admonishment to so many dog owners that animals are living in the moment, that as long as their current situation is one of comfort then they are generally going to be okay, and that they aren't capable of dwelling on unpleasant experiences like we humans are.
I guess the best advice for people who are going to take their pets with them is to just accept that you are going to be a wreck, and that more likely than not your pets will be less stressed and traumatized than you.
Heck, I'm still a wreck about it. Whenever I tell my story of bringing my cats over, I get teary eyed and emotional. My kitties just beg for more food.