I don't think twitter is a direct competitor with blogs. As stated in the article "One of the many uses of Twitter is to link to and promote your blog posts (and other people's blog posts, as we grow, so do they, and vice versa."So basically twitter is a tool used to generate or lead traffic to blog posts.<p>I read economics, business and web 2.0 blogs everyday. Some of the material cannot be covered in 140 characters or it will lack substance. What I do see on twitter is a headline to catch your attention and a link to get more information on another blog.<p>Twitter can replace blogs that lack substance, ie the teenage girl that writes about her boring life and stupid thoughts on her blog on myspace. This could probably be done in 140 characters or less.