NOW, today, this very second, it's no longer good enough to keep your standalone blog. You must throw in with the people around you who do similar things. You must build value. You must deliver something consistent, useful, powerful, that will reach the audience who likes your stuff, in such a way that it engages you.Then again you could also just keep posting to your own blog, for an audience of one. I like Chris' enthusiasm for bringing people together, but I don't see the urgency.
Why isn't a standalone blog good enough?
I think that everyone has a story to tell and collaborating is great, but maybe the content can live in both places. Both on personal blog site AND on a group site.
Take a look at Universal Hub. Adam Gaffin reads 100's of Boston area blogs and highlights his favorite posts.
Why must you build value?