The base price is going to be mid 50s. BMW isn't stupid. Look at the pricing increase on the M5 and look at the pricing difference between the E36 and E46. Mid 50s is where it's going to be. Now with options the car will easily hit 65-70K if you load it up (SMG, PP, NAV, etc).
But, I for one am not interested in loading it up. Whether you spend almost 70k on a loaded one or 55k on a basic one, it's still an M3.