Seth puts together some clues:
RSS fatigue is already setting in. While multiple posts get you more traffic, they also make it easy to lose loyal readers. Blogs with restraint, selectivity, cogency and brevity will use attention more efficiently and ought to win.
I think about this stuff a lot. Now that we can know just about anything updated hourly in real-time through corporate media channels, independent media channels and from citizen media channels, what does it get us? I still think one of the primary successes of blogs (and the net in general) is the microniche-ing and segmenting. That as publishing costs drive down, the ability to serve smaller targeted groups of people becomes easier and easier.
At the same time, I think blogs with cheesecake, beefcake, gambling and God will win. Not necessarily all on the same site.