Petfinder has put together a new list for 2011 of pet friendly airlines, and there is another rabbit-friendly air carrier that we can add to the list.
I was pleasantly surprised to learn that pet rabbits are allowed inside the cabin with you on Continental Airlines. Unfortunately, they were the only airline on the list that allowed rabbits in the cabin if on the plane at all.
Pet Airways offers a pet-only travel option as well. The cabin is climate controlled and all animals are monitored and taken care of by attendants.
For the full pet-friendly airline list, see: Petfinder.com.