I believe that prices will always rise on the very hard to find "in high grade" books like Action 1, Detective Comics 27, Showcase #4..etc There will always be a demand for these books.
For the rest, I still believe that a modest rise in prices will continue. While the market buyers are "graying", there will always be some to take their place.
I've always heard things like "What! XXX for that book! You've got to be kidding me!",. Ten years later, we would all jump at the chance to buy the book that cheap again.
Some books will take a nose dive, just because their prices were soley based on speculation(a movie, TV, etc) and not on the art and/or storyline.
I believe some books that look worthless today will become the high dollar books tomorrow( 15 years+), due probably to very low print runs.
All in all the comic book market will continue to survive and flourish albeit at a slower pace.
Anyway that's what I think.