Yes, you can see who's purchased tickets and how many of the 450 have been sold (about 90).
For me, seeing friends already signed up was a definite selling factor(Dave Winer has two seats, according to this, for example), but it also struck me that this experience applied a very wiki-like experience to event ticket purchase, which I think is cool--and a good fit for this event, which is all about capitalizing, even savoring, the flash of the moment.
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