I agree completely, Sinclair....except that I'm one of those who hates the Finder. It's not that I hate what it does, it's just that it has so many bugs and quirks and general backwards-ness. To this day, it still feels like a poorly ported OS 9 program which is exactly what it is. I really miss the OS 9 Finder. If you look at any of the features the two share, OS 9 will almost always have the better implementation. (And I'm still waiting for popup folders, darnit!)
So I hate the OS X Finder, but if Apple changed the fundamentals of it, I'd probably have a fit. Unless they made it work reeaaaally well, of course, but I can't imagine anything based on Spotlight working really well on such a scale.
I'm very optimistic, though. I don't think Apple will, or even COULD, ditch the hierarchical filing system. I think anything they do will be an evolutionary advancement of what is already there, an addition, or simple polish. There's a lot of room for all those things.
Anyway, as far the release date, I think Steve Jobs said last year that it would be out in 2006. If they were going to release it in the summer, I think they probably would have previewed it at their last big event. I think Burns is right: We'll see more at WWDC in August, and it will probably be released late 2006 or early 2007.