TUAW reports that the Thunderbolt controller in the MacBook Air is much different from the one found in the 2011 iMac, MacBook Pro and Mac mini line.
To fit a Thunderbolt controller in its thin chassis, the MacBook Air includes a controller that is half the size of the one found in other 2011 Mac models. Codenamed Eagle Ridge, this smaller chip includes two Thunderbolt 10 Gbps channels (instead of four) and one display port output (instead of two).Apple using smaller, cheaper Thunderbolt controller in MacBook Airs
