I think it would be cool if new users could enter their interests when signing up, and be presented with a random list of 10-20 people whose Twitter profiles have been categorized with those interests. That would be a pretty cool and effective way to "quick start" one's usage of Twitter.
The article also made me wonder if the same thing could be said of Facebook, where people who find Facebook shallow do so because they simply have shallow Facebook friends. My initial hunch is yes, although Facebook has much bigger problems with regards to the kinds of "look at me!" behavior it encourages. But that's probably another conversation. :)