It's quite intriguing...I like the free-form tagging it allows, and the multiple ways you can slice-and-dice the information. By list author, by keyword, by date, etc etc. I've signed up, and you can see my (still nascent) list o' links under my mamamusings username. I'm particularly intrigued by the RSS feed associated with each list of links, and am thinking about what the best way to aggregate and display these would be. I sense a need for a new application--an aggregator that collects links from the site and dumps them into a database or searchable environment.
You can subscribe to friends' linklists already, and there are some interesting social features built in--for example, the more people who have linked to a site, the darker the background for the link. What would make this better for me, however, would be for the weight to be determined only by the links of people I've chosen to subscribe to.