I'm taking mine on the plane as a carry on. When I made our flight reservations I asked about it, because I was a bit worried that I would have to hold it from Halifax to Orlando! The woman assured me that not only would it definitely go in an overhead compartment, but that the flight attendants would try to get it in its own overhead bin. If that wasn't possible, she said they'd rearrange things so that my dress would be able to lay over small bags in its garment bag.
After she said all that she actually said "You're our customer, we want to make your flight as smooth as possible for you."
I was unaware that customer service like that existed anymore lol.
Yes, first class offers an area to hang stuff up. My sister also had a dsetination wedding and when she caleld the airline to ask what to do with her dress, they told her that if on that day, there was room in first class to hang it, she could, but that they couldn't guarentee it. She ended up just putting it in a suitcase as her carry-on (her dress was really simple). I looked into upgrading to first class as well, I figured it would be a nice treat, but the flights were WAY more expensive than what I was thinking!
Thanks Lurkyloo!
I had my bridal salon pack it up in a box that was airplane carryon regulation size (just got the measurements from the airlines website which was Jetblue and they were very accomidating) and carried with it me the whole way from JFK to the GF. Since I was getting it steamed by Carolyn Allen the morning of my wedding anyway I did not mind if it got wrinkled. The salon just put it in the dress bag in a standard brown box and attached a handle. It was real easy to carry through JFK and MCO. I just placed my dress in the overhead directly above my seat. Once I got to the GF, I hung it in the bag in my closet. DH would never peak so I was not concerned he would see it. Talk to your salon about this option. 
My daughter was married in Disney last October. The airline told us that they may or may not have room for it as a carry on. I had a visual of lots of carry on pcs of luggage being stuffed in an overhead with a dress. My daughter flew down with her dessert party gown, I took the ball gown for the ceremony. There is no way I was letting that dress out of my sight. I bought a ticket next to me for the dress. When I walked on the plane the flight attendant said, "Uh, not sure if we will have room for that today." No, worries it had it's own seat. Funny thing is because it was so long, I was required to give the dress the window seat as I was told I had to keep the floor in front of the seats and the aisle completely clear of the dress bag.
Got from WI to Detroit, and guess what? No flight to Orlando anymore, had to fly the next day. Luckily, I was going 2 days before the wedding. I made the airline get me a hotel room with 2 queen beds so I could spread the dress out on the bed. I am so grateful that the airline screw up didn't have that dress sitting in either Orlando or Detroit overnight.
I also reserved a seat for the dress on Magical Express! Keep in mind that maybe you only need a 1 way ticket because once the wedding was done, it wouldn't be such a crisis to have the dress "misplaced" or delayed. We had friends who drove to FL take it home for us.
