Because of Ohio Dream's insurance they had to be open for a certain amount of time before they could get trampolines.  I know that that time is either up or close to being up, and tramps are definitely in the future, but for if they will have them this summer I do not know.
One benefit of Ohio Dreams is the lack of people.  Skiers and snowboarders get in countless hits a day on the ramps because in the summer the ramps are limited to only campers.  The coaching is also very good, and the level of skiers at camp ranges from never before snowboarded (not recommended for water ramps, guy just had balls) to recreational and competitive kids to nationally known am and pro skiers.
Also the water ramps at Ohio Dreams are freestyle PARK designed, unlike Lake Placid or Park City.  They aren't mogul jumps, they are park jumps.  Ohio Dreams is the only place in the nation with water ramps like this, which is why some skiers travel a long ways to hit them.  There are three sizes and the tricks that are thrown can be ridiculous.  If you ski park it is way better to learn your tricks of a water ramp that is cut the same as the jump you are hitting versus a mogul aerials ramp that throws you differently.
Let me know if you have any questions,
G