Some behind the scenes pics from Vancity Filming give as a better sense of what goes down in that scene — and confirms that Emma does, indeed, see Neal.
In the photos (which you can see here and here), the city of Vancouver has been transformed into New York, with "SoHo" signs and New York City yellow cabs. According to the eyewitness on the scene, the cast and crew filmed Emma chasing Neal into an alley, which seems like it's the scene we see in the promo.
The question is: Does this mean Neal is Rumple's son, the way the preview implies, or is there something else going on?
Find out the answer on the next episode of Once Upon a Time on Sunday, February 17, 2013 at 8 p.m. ET/PT on ABC.