I generally liked Michael's article and enjoy his insight, but one thing that rubbed me wrong was this:
Now, Sony has kicked everyone's ass (or at least will in a year or so when they have a proper slate of lenses available to go with their new mirrorless full frame system).
I don't really like predicating a declaration of greatness on something that hasn't happened yet--much less a full year or more out. I am a "show me the money" kind of guy, and I want to see those lenses in operation before I declare the Sony full frame mirrorless cameras a smashing success.
I think it is interesting to compare the Leica full-frame rangefinder lenses to the M43 lenses because the Leica ones cover full frame AND are more compact than traditional SLR designs. I think the big question about the Sony full frame mirrorless initiative will be whether they can really realize a Leica-like quality and compactness with a mass market volume and pricing. The answer to that question is at least a year out, so the answer to whether the A7r is great is also a at least a year out.