I happened across an interesting article the other day in the Times of London. The article, entitled Meet blook, son of blog, on the new frontier of publishing, describes an avenue to publication that didn't exist until recently. Blooks are publications that have sprung from a popular blog or website.
It makes sense, really. An established blog has an established audience, and a traditional publisher, risk-averse by nature, can mitigate the risk of taking on an unpublished author by selecting one that already has a large fan-base. Marketing dollars can be saved because there is already a conduit to a portion of the target demographic.
If you already have a popular blog, you might want to think about using it as a path to traditional publication. If not, then you might want to think about starting down that path.