The Wikipedia defines Blogosphere as “the collective term encompassing all weblogs. Weblogs are heavily interconnected; bloggers read other blogs, link to them, and reference them in their own writing. Because of this, the interconnected blogs have grown their own culture. The term was coined on September 10, 1999 by Brad L. Graham, as a joke. It was re-coined in 2001 by William Quick (quite seriously) and was quickly adopted and promulgated by the warblog community.”
The blogosphere can be considered a giant community of practice. As the wikipedia points out, the initial main interests of this growing community are politics and technology. Now, with expanded use of blogs many new topics are emerging and, by extension new opportunities for communities of practice around these topics. I think it is limiting to only think of blogs in terms of their conformance to the culture of the first community of practice, since there are many uses beyond politics and technology. This is not to be disrespectful of the contributions of this first community nor to reduce its value. I certainly continue to learn from these orginal blogs.
I think it will be beneficial to welcome diversity here, to be open to new uses, and to recognize and support them. For example, blog services that rank blogs by usage, like Technorati, generally look at blogs as one group so the blogs connected to politics and technology will generally raise to the top.
It would be useful to be able to easily find the top rated blogs by categories such as travel. food, music, fiction, and the arts. You can get a bit of this by simply doing a Google search on a topic but it still requires some digging to get to the good stuff.
Forbes has made a start but their ratings are more the personal thoughts of the rater. Here is a prior post on some other ratings available. Technorati has made a start with its book list of the books most talked about in blogs, along with several news related lists. The opportunties to be helpful here are large.