There are a very few excellent, and interesting, blogs; but there are far more lunatic/boring/crackpot ... (extend list to suit yourself) ones. A problem that occurs is that without a "theme" many blogs degenerate into useless drivel, and with a theme they tend to degenerate in advancing some political/religious/mystic etc. preconceptions.

i.e. the generalist ones that survive, especially those related to "news" or "politics" tend to become less balanced as they develop a "party line." With a healthy BS-detector, it's pretty easy to spot some of them, but it's just as easy to apply the same detector to conventional sources and extract useful info - just by assuming that "if what they say is all lies, the truth must be ... ."

There is also a been trend for blog "sponsors" to begin looking for ways to make some money off of their sites, so some see a limited future for casual blogging. A few decent blogs have already been "killed" by this process.

John