My mom's had Corian in her house for over ten years. The kitchen doesn't see heavy use, and it's pitted, etched, scratched, stained- you name it. Perhaps the formulation has changed over the years, but it's not something I'd be willing to try again- especially with the integrated sink. Her white sink is about the most disgusting thing I've ever seen.
A lot has changed in ten years, and there are many more options on the market. For my needs, I'd consider Corian about as much as I'd consider Formica laminate.
What are the chances that we'll use granite several years down the road when we build the next house? Probably slim- but it's not because we don't like it. With all the options out there, we'll probably be drawn to something a bit more "green" by that time.