Not too long ago, Apple released the second iOS 5 beta. In this update they enabled Wi-Fi Syncing. To use this new feature, you must be running Mac OS X 10.6.8 or later, have iTunes 10.5 beta 2 installed, and be running the second iOS 5 beta.
If you have all of the above then you can follow the steps below to enable Wi-Fi Syncing.
Plug in your iDevice and go to its summary page in iTunes. Scroll down to the Options area. Check the box next to Sync over Wi-Fi connection and click Apply. Now to sync wirelessly, make sure that iTunes is open and that you are on the same Wi-Fi network as your paired computer. Open the Settings application and go to General > iTunes Sync and tap Sync Now. If you have done all of the above correctly, your iDevice will now start syncing wirelessly.
