The Sony NEX-7 is very skinny on the ground given the horrible flooding in Thailand. My contact at Sony fears that stores won't be seeing new gear until February at the earliest. The folks at Leica explain the absence of pretty much every one of their M lenses on "market demand". Why? Because folks are buying newer mirror less cameras and Leica adapters to use M lenses.
No doubt about the quality of the Leica glass, but what happens when you put Leica glass on the hot new NEX-7? The people at Luminous Landscape have done it in a multi-part assessment. Follow the link to read the article 15 December, 2011 - NEX-7 vs. Leica M9 Resolution