I guess I interpreted this question a little differently, as in what has been overlooked that could stand to be fixed. In my opinion, shade! Especially along the Main Midway and in the Iron Dragon area, there are far too few trees for shade. Those umbrellas don't really do anything. People are forever getting heatstroke and sunstroke, and while there are things you can do yourself to help prevent that, having a shadier pathway to walk on would help tremendously. Going from the Midway back to the Frontier Trail, the temperature drop is noticeable.
As in good stuff that is overlooked, I agree with a lot of what's already been posted, but I'll also say 2 things: the lookout deck by Thunder Canyon, because it is so classic to watch the rafts go by and laugh at the people that didn't really believe they'd get wet on the ride. #2: The beach! That is, after all, what Cedar Point was first built as a resort for, and it is really a superb beach - soft sand, nice and shallow for a long way out, pleasant water temperature, and it's a shame that more people don't add that extra day to appreciate it!
-------------
PO!NT OF VIEW - A Different Look at Roller Coasters
http://www.crosswinds.net/~justmayntz/thrills/