What is the connector used by the MBA's SATA drive?
It is a variant of Mini PCI Express &amp; mSATA:


  Some notebooks (notably the Asus Eee PC, the MacBook Air, and the Dell mini9 and mini10) use a variant of the PCI Express Mini Card as an SSD. This variant uses the reserved and several non-reserved pins to implement SATA and IDE interface passthrough, keeping only USB, ground lines, and sometimes the core PCIe 1x bus intact.[11] This makes the 'miniPCIe' flash and solid state drives sold for netbooks largely incompatible with true PCI Express Mini implementations.


Source: http://en.wikipedia.org/wiki/PCI_Express#Mini_PCI_Express_.26_mSATA