In this same vein, I just finished reading an article in the latest College & Research Libraries (Mar 2010, no. 2) "What are they learning? Pre-and post-assessment for LIBR I 100, Introduction to Library Research" by Jon Hufford. They did tests of students before and after an information literacy course.
What I found interesting were the results concerning users' understanding of the library catalog e.g.:
"What is the least likely resource to use to find citations to articles?
A - library's online catalog
B - electronic databases
C - internet
D - search engines
e - periodical indexes
Pre: 6% chose a. Post: 28% chose a.
"It is possible to find full-text magazine articles in the library's online catalog." True-False
Pre: 18% chose False. Post: 22% chose falso.
And most telling:
"Which of the following kinds of information can be found in the Library's online catalog.
A - journal articles
B - journals the library owns
C - books on a certain topic
d - book reviews
e - sound recordings the library owns
Pre: 4% chose b,c,e. Post: 5% chose b,c,e. (I would have emphasized "catalog records" for journals, books, etc. the library owns, not the books themselves)
In fact, from this entire report, the students appear to show a much greater understanding of the digital materials and tools than the traditional library materials and tools. This mirrors my own experience. Young people (most people?) don't know what they are searching when they search Google vs. Google Books vs. Lexis-Nexis vs. an OPAC ... [et al.]. When I try to explain the differences of what they are searching in each database when they enter text into the search box, I see they are struggling, and I find it extremely complex to explain. I still believe that the traditional library catalog is becoming increasingly strange to our patron community.
I have tried to solve some of this with the Extend Search in my catalog to at least make it simpler to search all of these different places, but you are right: there needs to be a lot of serious work in interface design.