O'Reilly Radar's Ben Lorica surveys current micro-blogging trends in When Micro-blogging Grows Up, reporting that three categories, technology, tech/personal, personal, accounted for 56% of the total "subscriptions" to the top 100 Twitter users. Political micro-blogs are less represented than in the blogosphere generally and there are substantially more liberal micro-blogs than conservative ones. Lorcia writes
Once more stable services and business models emerge, I still think micro-blogs will evolve to share some of the properties of the blogosphere described above. Micro-blogs from traditional media sources will be among the most popular. The liberal vs. conservative split will be less pronounced, with conservatives narrowing the micro-blogging gap. The top micro-blogs won't be as dominated by technology, although I'm not sure the format is really ideal for political topics.