Agreed that they were checking for several individual factors and the one on one was just for our closure/giving us the final word. I went last in my group so was fortunate enough to have more like 15-20 minutes. We had a brief discussion about how with traditional interviews, half of the time admissions isn't getting to hear much more than they could already discern from your resume, essays etc (assuming you presented a well rounded package). The TBD allows for some of those intangible skills to be demonstrated rather than stated.
All in all, I really liked the TBD and think it will stick around. As it was the fist year, it will be interesting to see how they use the data, but it is a definite differentiator for Wharton. I also found it refreshing to not have to talk about myself for 30-45 minutes straight.
Now for the wait... If anyone here has ever competed in a judged sport (gymnastics, diving, etc) you know what I mean when I say that waiting for the final score is 1000x more anxiety inducing than any of the prep leading up to the competition or the task itself...