Wow, I kinda suspected that Digg was killing Slashdot lately, but check out the comparative graph of “People” from Compete:
The number of people in the U.S. estimated to have visited a domain. People counts are also known as unique visitors – they only count a person once no matter how many times they visit a site in a given month.
I guess all the media attention Digg has gotten lately, combined with the fact that it’s more than just technology news, is driving all this traffic. Still though, that’s a pretty huge divide! 
(Thanks for the Compete hat-tip fuzzz)