It's been a while since I first asked and the new App-Search product got me wondering again.
Here at work we have many different tools being used to store information. Our only search is either the tools built-in engine, or Google Custom Search for public content. I'd love to have a search engine that could index all our different tools, and then only display results to the user that the user is authorized to access.
So, an employee could do a search and get results from PBWiki's they are members of, and a student could search the same term, and they would not get results from the PBWiki's.
Anyway, I hope that describes what I'm looking for well enough.