I just had it happen to me this morning as well. I was in lane 2 of 3 going approximately 60-65mph trying to get to 70 when the transmission shifted into neutral. I doubt clutch was slipping as no shudder and no CEL type warnings. Car coasted down to about 15 mph before tranny re-engaged a gear. I tried to shift into L and N back to D, with no effect. This is very scary in morning traffic passing on both sides. I have an appointment on Weds with the dealer.
The car is less than a week old for me and had 550 miles on the odometer. Not Happy.
2013 SFE, built 7-17-12.