Went there yesterday. It was cool and different for the first 5 minutes (i.e. drinking from an ice glass) but got boring pretty fast.. and then we were just cold and wondering why we paid to experience winter temperatures in the summer. My mistake.
Our AMEX deal offered a "signature dessert" which just turned out to be Breyer's Ice Cream with M&Ms sprinkled on top served on a plate.
Toronto has it's share of cold winters so I don't see people wanting to pay an admission fee for this.