On some level (and this has been already noted), I believe we're all a little guilty of nostalgia coloring the lens of how we are evaluating the old sets in comparison to the new ones. That being said, I find myself preferring the old sets like just about everyone here. I don't think the new sets are fundmentally inferior in any way, but they do lack...something. Hard for me to put a finger on it. More than anything, the new sets feel more cartoonish than the older ones. Somehow, more plastic and childish. Don't know if this makes sense, it's just the feeling I get.
The introduction of medium-sized ships, more Imperial sets, and some kind of new element (Aztecs? With pirate curses? More developed Spanish-looking sets? A great pirate port town?) would be immensely appreciated and would siginificantly change my mind about the new sets.
If the 2009 sets are only a start of many things to come, then it is a successful series. On its own, not so much.