I don't think this ride is as easy to build as some believe, especially with it in the middle of the park. They need to get all the plumbing and electrical in order, not to mention do some major overhauling of the landscape. The area where they're building it has been supporting other things such as the Carousel Barn and the Balloon Chase. They have to clear all of that out before they can do anything. Also, the sign says Spring '09 for its debut, so it definitely won't open this season.
I do believe the Carousel Barn and Balloon Chase will be moved before long. Copper said in the captions of the pictures of the new ride construction that they will be back online soon.
As for another new ride in '09, such as a coaster, I don't think so. But maybe. It's a possibility. The only markers anyone has seen (as far as I know) are the ones over by the Expo, and I agree with Steve. I think those are for the Balloon Chase and maybe Carousel Barn. The only area I think the new coaster might go is out beyond the Giant Swing. But maybe those markers by the Expo are for a new coaster. We'll have to see. It's interesting that they have the teaser fence up and the online map (I'm assuming also the physical map) marked for the new ride. Yet there has been no official announcement. Nothing. Maybe they're waiting for the results of the concept survey so it'll have a name. Or maybe they're holding their cards for an even bigger, two new rides for '09, reveal...
It'll be interesting to see what happens. I wonder when they will make the official announcement?