The monograph From Keyword Search to Exploration: Designing Future Search Interfaces for the Web  by M. Wilson et al. lucidly reviews the current state of search interfaces that move beyond the traditional list of results. We've included some choice quotations below.
On why we need better search interfaces and systems:
Even more recently, though, researchers have identified just how inadequate the familiar keyword search paradigms, provided by environments such as Google and Bing (Microsoft's search engine), might be for users who need to do more than just find a website that answers a factual question. (p.9)
Exploratory search scenarios are characterized by needs that are "open-ended, per- sistent, and multifaceted, and information-seeking processes that are opportunistic, iterative, and multitactical" . [...] It is plain to see that a search interface needs to provide more than a simple keyword search form to support users in applying such strategies. (p.10)
On problems with new search interfaces:
[After evaluating textual and non-textual layouts] the conclusions were that web search results lack "1)... a natural spatial layout of the data; and 2)... good small representations," which makes designing effective visual representations of search results challenging. 3
Additionally, here are links to some of the mentioned projects we found interesting and unique.
 Max L. Wilson, Bill Kules, m.c. schraefel and Ben Shneiderman (2010) "From Keyword Search to Exploration: Designing Future Search Interfaces for the Web", Foundations and Trends(R) in Web Science: Vol. 2: No 1, pp 1-97. http://dx.doi.org/10.1561/1800000003
 R. W. White and R. Roth, Exploratory Search: Beyond the Query-Response Paradigm. Morgan & Claypool, 2009.
 W. Rivadeneira and B. B. Bederson, A Study of Search Result Clustering Interfaces: Comparing Textual and Zoomable User Interfaces. University of Maryland: HCIL, 2003.