Probably just the painted bits on the motor cooking off...not abnormal for new cars.
My wife and I have been following the break-in procedures per the manual and used a few interstate on-ramps to "quickly accelerate" as they say. Each time we've done it there is a burning/burnt smell coming through the air vents. It's not present any other time. We purchased the van 2 weeks ago and it has just over 700 miles on it. Has anyone else experienced something similar?