I don't think anyone besides geeks would use something like that. Google says very few people use the filtering functions built into their search. You have to t

I don't think anyone besides geeks would use something like that. Google says very few people use the filtering functions built into their search. You have to take it to the Monkey Island level first, perhaps, where there is a way to build a query? The average person won't take the the time to learn or remember a complex syntax for a search engine. A powerful search syntax is a good idea. It could be something as simple as a frontend to another search engine's API. As far as natural language search, though that's the goal of sites like ask.com which have been around for a long time now.