Blogdex may be offline (or, maybe back on now?), so try out the BlogsNow aggregator for its general aggregatory goodness. Includes categorization of links (MP3, flickr, Wikipedia, etc.). I may be out of the loop, but why aren't there more Blogdex 2.0s out there?
Good question. I think one reason why there are not more "Blogdex 2.0" applications out there is that managing spam got very hard. Blogdex V1, as well as Daypop have their own (little) list of blogs they crawl. Those were almost handmade "back in the day".
Now you have 90% spam blogs posting: Have a look at weblogs.com Very tricky to get a handle on that.
The other aspect was that aggregators used to be hip and new at one point and got lots of attention.
That has moved on to flickr and Co. Which is only fair enough I think. But there still is a need for a blogdex like service. I at least visit BlogsNow way to often ...