I agree with you. I noticed something about Delicious: when I add a URL, it's rare that someone else hasn't already bookmarked it. That means that Delicious has, to a first approximation, everything interesting on the web. All organized by humans in a rich way. That's an astonishingly valuable data set. Relative to that value, the use that's being made of it is so low it's criminal.

Even if they aren't capable of evolving it, I wish Yahoo would at least make it fast enough that I don't cringe every time I use it.