It could get more mainstream as more dynamic information can be shared via "dropcards" than on business cards. I think it's a pretty good idea, but I would prefer business cards.
If someone is working with business cards and gadgets, they really need to try it in Japan. Business cards are extremely important there, but they have many early adopters in the population, too. See http://en.wikipedia.org/wiki/Meishi for more information.
Well, I think this is a great idea if you consider the importance of business card against the idea that the business card holds all this contact info that you're going to get anyway.
Aren't they using the same shortcode as chatterous.com?
It's running on TextMarks probably until they can spring for a shortcode.