I enjoyed hearing Nina Platt's tech-savvy librarian's perspective on limitations of search, and the skills that a good librarian has. (I also enjoyed chatting with her and her new employee at Legal Tech08).
I certainly agree with her that, if you're trying to find anything at all unusual or difficult to find, a librarian or skilled researcher is going to be miles ahead of a typical search engine. The libriarian / researcher can grasp and then supply the real context to the query, through iterative questions that the user hadn't thought or didn't know to ask.
I serve as something like a librarian with respect to my firm's internal work product resources, and I have found myself using a similar "patter" when people call looking for a sample brief or statistics on patent litigation. I can help much faster and more effectively if I know why they are asking, including (usually) the specific procedural stage of the case, the jurisdiction, and which side we're representing. Usually the first email doesn't have everything I need to search effectively.
I can't help but wondering if the combination of social search and faceted / guided navigation will bring search a little closer to what a librarian does, by showing some of the possible contexts and refinements. See my previous posts here and here on Vivisimo's entry into the field.
With such a system, not implemented at any law firm yet so far as I know, if the clueless associate searches for "motion to dismiss", they'd get a half-million results. If they can then see and refine / filter by tags other less clueless associates applied such as "jurisdiction" "forum non conveniens" "particularity", not to mention metadata attributes such as forum, they may be led down the right path almost as accurately as a libriarian or practice support / KM attorney might take them.