Loved it as a kid as well. It had a resurgence recently in the US with a rebranding/re-packaging, and I believe they switched to cane sugar. It didn't last long. As far as I know they are now defunct in the US. Not sure if it still exists in Canada still or not.
I love beverages and CC was always one of my favorites. Clearly Canadian and Mystic for life.
EDIT:
The best evidence I can find that it doesn't exist...They advertised this as their website as recently as 2 years ago.
www.clearly.ca.
That links to a contact lense site now. Oh well. They didn't make an energy drink / energy shot soon enough. Gotta keep up with the Jones'. Yes...I know that's a soda brand pun!