Was trying to set up my brand new macbook air with thunderbolt by transferring my files from my brand new iMac 27'' with thunderbolt and Migration Assistant was only giving me the option to transfer using wifi. Lame, because this would take 14 hours in my case. Called Apple Support and after a lot of time "checking documentation" the conclusion was: we do not support transferring of files using Thunderbolt as yet. Kidding, right? I was left very disappointed, but actually found out myself how to do it: On the iMac: reset it keeping "T" key pressed Connect iMac and Macbook air using the $40 thunderbolt cable by Apple (no cable no solution other than wireless or an external drive where you have a time machine backup, usb only) On the Macbook air: run Migration Assistant and ask to transfer files from an external hard drive as it will recognize the iMac as an external hard drive. It works, but I had to figure it out myself.