That’s the theory behind Guy Kawasaki backed alltop.com
The site lists categories such as celebrity, gaming, mac and egos – “Featuring the mouths, minds, and egos of folks like Scoble, Cuban, Trump, and Winer.” (small business is coming) and then aggregates for you a collection of what are known to be some of the top blogs on the subject. It makes a handy little portal for surfing some of the more popular sites.