Is Stackoverflow.com really a Web 2.0 site?

Stackoverflow.com has only really done #1 of the first 3. However what I really want to have a discussion on is if it really has advanced it self enough beyond the old forum model to really be considered 2.0 worthy or is it just a display layer on the 1.0. For all intents and purposes we are going to use the forums on ASP.NET for comparison.