There were very little doubts about that : the Fujifilm X-Pro1 target is Leica and its rangefinder range like the M9 and now the M Monochrom. Today, Fujifilm launched the adapter ring that will allow X-Pro1 equipped photographers to use Leica M lenses and more widely, all M mount lenses. The adapter made of aluminium and stainless steel gets electronic contacts to ensure the lens and the premium mirrorless camera. You have to push a button to let the EXIF datas flow from the lens to the camera body. Most Leica M lenses have been profiled by Fujifilm to offer in-camera lens correction (distortion, vignetting and chromatic aberration), corrections that you can edit and adjust their level.
To use this $199, £179, €179 Leica-M lenses for Fuji X-Pro cameras adapter, you will have to update the firmware of your camera to the version 1.1. This adapter is fully compatible with the X-Pro1 smart and great hybrid viewfinder.