Yesterday was my first day out wit the OM-D E-M5. In regards to the fuji x100 this camera is fast, incredible fast. Feels even faster then the D800. No issues at all with the focusing it really works, point shoot. No delay nor hesitation as with the x100. Of course with the x100 it felt more as a film camera, with the OM-D E-M5, is more like a gun, :). I am using the battery grip so its quite comfortable to handle and still small enough to pass un seen. Might not look as much as a film camera, but still has its old school looks which helps in the street.
Picture quality is nice, as mention before i think the x100 still has the edge in this department, more tests will need to be done. Shooting through the evf is better then i though it will be.
Some images from Sao Paulo, all shot with the 12mm 2.0.