Oh, I agree with many of you about the cell phones but I would love the Wi-Fi. As a frequent flier to Asia from Eastern USA, I am flying about 26 hours (air and transfer time) each way to reach my destination. Many times, I am already trying to start adjusting my body time clock to my destination and Wi-Fi would be a great help. To be able to work on emails and other needed areas on the plane would be great and help me to stay awake and alert. When there is nothing to do but watch movies, read a book or work offline - well it is so much easier to fall asleep. I don't think me pounding the keys of my laptop would really disturb anyone else which a cell phone would definitely do. Even just the ringing of the blackberrys and the cell phones even if they were not answered would be a nuisance.
By the way, Cathay Pacific offered this in years past on their planes but I have not found it recently.
Apparently you can VoIP on Aircell, which is the provided of the airborne inflight broadband for American Airlines. Guess it takes a little techy knowledge to effectuate this bootlegged service.and Aircell will likely figure out a way to block it shortly.
Also, kyshel, Delta will apparently become the first US carrier to provide the service throughout the entire domestic fleet during 2009, while American is on a slower roll out of their fleet wide service.