Source : FrenchiPhoneApple did not want to do it, so others took charge. It is now possible to synchronise an iPphone without having to connect a wire to a computer.
It is necessary to install an application called wiSync on the Mac, and wiToggle on the iPhone.
The sync can then be programmed and will work as long as the two devices are connected to the same WiFi network.
http://modmyifone.com/wiki/index.php/WiSync
One can see what will be the next step: to find the means to communicate between two iPhones and to exchange files between the them. In summer to recreate the social system à la Zune. But Apple and surely the record and movie industries might not appreciate this at all.
[translation by jwa]