Jeff Atwood links to criticism of how certain kinds of searches (such as finding appliance reviews) have become so difficult on Google, and I'm running into a similar problem with StackOverflow. I've noticed two situations are starting to be irritating:
(1) I'll try to search SO extensively for the solution to a problem, can't find the solution (or even the problem), start to compose a question, and only then see (among the suggested "similar questions") that there indeed was a solution posted, but somehow my initial search attempts were insufficient to find it.
(2) Either by searching or asking, I'll find or be given a solution, only to later stumble upon some other posting with a "better" solution.
In other words, it seems to be getting harder to find the "optimum" answer as the content grows, just like the criticisms of Google. How will SO avoid this effect, or will big successful knowledge-based systems by definition always be more difficult to exploit as they grow?