A lot more detailed analysis has been posted here. Folks compared the new M3 to the M5, the 550 to the M5, to the 335i, the old M3 to the old 328, the E60 M5 vs. the E39 M5, the RS4, etc., etc. Folks have used exclusively US prices for scaling, US and foreign prices, just about every comparison under the sun. Most of those concluded high $50's. Some still are hoping and praying for low 50's and others are dead sure it will be $70k with a "few" "key" options. I never like those super vague estimates as they are open to complete interpretation.
I just can't decide which side of the very important 60k "psychological barrier" BMW will fall on. It is certainly "worth" low 60s in IMHO but they would probably sell. Assuming they can sell 50k cars at $62k they only have to sell 7% or so more cars (about 3500 cars) to make more money selling them at $58k. I think that $4k price difference would probably support the extra 3500 cars.
Don't we have an outstanding bet on pricing among a couple members as well??