Is the E92 M3 6-speed really geared that tall (73 MPH in 2nd gear, 111 in 3rd!!??). That is tall for a high-revving engine and does not take advantage of the revs. Maybe they are doing that for gas mileage.
The answer to how fast it will accelerate lies in the new Motor Trend magazine:
Porsche 997 Carrera S: HP 355, torque 295 lb ft, weight 3275, 9.23 lbs/HP
0-60 in 4.4, 1/4 mile in 13.0 @109.5
Porsche 997 GT3: HP 415, torque 300 lb ft, weight 3235, 7.80 lbs/HP, 0-60 in 3.8, 1/4 mile in 12.1 @ 118 MPH
BMW E92 M3:414 HP, torque 295 lb ft, weight 3483, 8.39 lbs/HP. The power to weight ratio is 9% better than the Carrera S and 7% worse than the GT3. With similar gearing to a GT3 (kinda tall in the 1st three gears), I see no reason the M3 will not fall smack in the middle of these. It will not be able to launch as hard for 0-60 due to less weight in the back, but I think 0-60 in 4.2 -4.3 seconds and 1/4 mile in 12.5 @ 114 is the best guess based upon the Porsche comparison.
Driving sideways: It's not faster, but damn it's more fun!