im not a developer, and i dont have a leaked copy so i havn't tried 3.0 out, but is it going to be like the spotlight on the mac where it searches the whole mac and has all the files in it, or is it just an application searcher, i wouldn't expect it to be, but i havn't heard anything that says it isn't

Yep, it searchers the entire thing.

Notes, Albums/Artists/Songs, Calendar events, (guess) Safari Bookmarks, Contacts, etc.