One of the problems with Web 2.0 is people reinventing the wheel. Without adding any real value, developers are recreating services with the latest technologies.
If you think of forums (discussion boards, bulletin boards, etc), you would probably assume that recreation would simply be using Ajax to load pages to potentially make things quicker. That might have some value, but not necessarily enough to warrant an entire recreation of refined products such as phpBB, Invision, or VBulletin.
Fortunately, the new guy on the block, Lussumo’s Vanilla, does not fail at including the latest Web 2.0 ideas. Here are just a few:
Emphasis on Content, Not Stats
There is not a straight forward features page on the site yet, so there much more to it than that. I suggest you check it out (sign in with guest/guest) to see the full affect.