I know that locally the marinas seem to be pretty full. Mid Hudson Valley wise West Shore appears to have the same number, as does Marlborough Yacht Club. In Newburgh the two remaining marinas seem sold out but what used to be Torches did not put out docks last year, though they did the year after Sandy, and their slips by Shadows seemed to be about sold out, and pre-Sandy they were at about 20% full. Does not seem to be any less at Whites (still sold out, though there are some damaged boats on the hard there, looked at a boat last fall that the companionway had blown open in Sandy, and the owner was not aware of it, needless to say the interior was ruined) New Hamburg Yacht Club seems full. Chelsie Yacht Club seems pretty full, but fewer boats sitting on the hard during season. Not sure about the Kingston clubs, as I was not up there much this last year. Hop-O-Nose seems full as well but it was end of season when I was there.
So from my observations it seems that many of the derelict boats are gone. So perhaps there may have been a bit of cleaning house. As was said serious boaters, either replaced with newer or seem to have snatched up the better boats that were not being used. I am sure many that were on the fence about continuing left if they could cash out.
Everyone I know that had a boat seems to have survived Sandy OK. There does seem to be fewer boats listed on Craigslist and what not.