to support the Kensington style lock but all is not lost.
This company, http://www.maclocks.com, the result of a Google search, have produced a locking solution for the Macbook Air and should have the Macbook locked down shortly.
Check them out.
I just bought a new Macbook in replacement of my old PC. I find Apple's strategy of removing the Kensington slot not convenient. How should i lock my new Macbook?