Ensuring high quality sources where needed, especially science/academic topics (narrow focus)

KrebMarkt is right that there are already a bunch of lists at different WikiProjects. Compiling them together is a good idea. But I stand behind the idea of turning that list into searchable results, in the form of a specialized web search engine.

Yes, in an ideal world, people would be searching books too. But being able to quickly see how a concept has been covered in the BBC or even CNN would be a huge improvement. The biggest problem with quality isn't that people are misusing or misweighting good sources -- that's an important problem, but it's rare. The biggest problem with 90% of articles is that they aren't using any sources at all (or that they've become a soapbox to rehash what someone said on some blog).