Metabones - Metabones and Caldwell Photographic introduce Speed Booster
An adaptor claims to make your lens, faster, wider and better!! This is NOT an April Fool’s! | Philip Bloom
Speed booster for NEX - The GetDPI Photography Forums
They also mention supporting Leica R in the future.
Sony NEX System : Leica R Lens to Sony NEX Speed Booster
Here is a more jaded view:
METABONES | Speed Booster - The GetDPI Photography Forums
Edited by k-hawinkler, 14 January 2013 - 09:22.