We've been doing similar things at Duck Duck Go (http://duckduckgo.com/) to these new Google changes. In particular, we put zero-click info, e.g. topic summaries, on top of links. We also also put an explore box with related topics above links. For example check out
http://duckduckgo.com/?q=futurama
Our snippets and related topics are not algorithmically driven, however. Instead they are based on human edited sources, e.g. Wikipedia and Crunchbase (and many others). Consequently, they are more relevant and make more sense than Google's info. We also have more semantic properties, such as ambiguous keyword detection, e.g. http://duckduckgo.com/?q=apple, which of course Google does not.
See
http://duckduckgo.com/about.html for some more examples. Of course, we'd love your feedback on what we're doing.
Gabriel Weinberg, Founder & CEO