Is Web-based Exploratory search on the increase?

I read an interesting paper by Vakkari's team, on the different queries submitted to libraries via an online form, between 1999 and 2006. The trends are quite interesting, and one of the conclusions is that topic-related searches have reduced in libraries because they are, instead, being performed more on the web. This creates two questions about topic-searching on the web:

1) many HCIR style papers assume that this is hard to do on the web, but this research suggests its happening more anyway. This is perhaps because its more convenient to access the web now, than it is to drive across town. The service they analysed, however, was an online library query service (in Finland).

2) This is surely motivation for providing better exploratory search interfaces on the web, to help people explore and learn topics - why has it only dropped from 57% to 47%? Why not further?

They also conclude that people still turn to librarians for difficult searching problems. This really is motivation for providing better exploratory search interfaces, so that a) the number of topical searches to libraries goes down even more and b) so that the number of difficult questions goes down instead of up!