As I write this I am seat 23F on flight SQL 286 from Auckland, New Zealand to Singapore & am connected up to the Connexion wireless internet service. I did a speed test and got ~400kbps.
This is an amazing service. Being able to catch up on work and email will in the air.
Sad thing is that Boeing is pulling the service :( According the Connexion web site, it will all be gone by the end of the year. There are rumours that someone else will take over the service.
I certainly hope so. With net access it at least gives you something else to do once you have seen all the movies :)