One of my big concerns about SO is how sustainable it will be in the long run. We've all been part of other communities that compete with SO in the past and present and I'm curious why we think that SO "has that thing...". Some people say that Apple "has that thing..." or Google "has that thing...", but does SO "have that thing..."?
Why will SO succeed while others will not? Will SO outlast the ASP.NET forums?
"has that thing" = positive buzz, perception of cool, will not fail, etcetera......
Will new users continue to come to SO? Will advertisers continue to contribute money (of late I've notice quite a few "your ad here" messages, not good?)?