I am always looking for a buddy to dive Dutch. I live in the Philadelphia area, and have done a bit of diving up there.
As far as the temps are concerned, they are not bad. I was down at 95 feet there about a month ago, and while the face was painfully cold, the bod was just fine in 7mm FJ & hood. The visibility, as always, varies depending on when you are there (read: weekdays rule, early Saturday is good, Sunday afternoon rots). The proliferation of zebra mussels (man, they multiply FAST) has done wonders to the clarity. And the water level this year is very good -- a good 8-10 feet higher than last year, and probably 4-5 feet higher than the year before. Some of the weekends are really crowded, but it's no so noticeable underwater, beacause at any given time, most of the folks in the place are either on land or getting in or out of the water.
Let me know if/when you are heading up there. My schedule is whacked out this summer, but I am still planning a few more trips up there between now and October.