Yep! In the search field above the library window, press the "FT" button on the very left. You have to create the index the first time you use the feature. It takes a while and from there on new books are indexed automatically.

FT search has word and phrase search, boolean operators and NEAR search abilities. And there is a really cool match list, giving some context of the match before you actually go to it in the PDF file.

You cannot search across libraries, though.