It looks like United, of all carriers, is the first to announce Wi-Fi access to its passengers in flight. Pricing has not yet been set. Other airlines might still be the first to implement such access. United does not expect the access to become active until mid- to late 2006.
I am keeping my fingers crossed that other airlines will follow suite. Expect the airlines to charge a premium for the access as they are all trying desperately to better their bottom line.