Doctor Scoble poses a provocative question: "Which aggregator do you like best"? Quite an amazing variety of aggregators are mentioned. It might be the most crowded space I've seen in a long time.
Gee, and my own project, BlogBridge is in the space. Of course, we are willing to take on all comers because we feel that we've got a better mousetrap, and that we've pushed the envelope in some really important areas. But you know, I bet all of them feel the same way.