Considering how amazing her album was this past year, I trust her in making a good well rounded album. If she wants any type of commercial success though, she would need to make sure she had singles lined up and ready, as well as have her management/promotion in check. That and her personal life really bit her in the butt last era.
I personally think she should take some time off, but Mariah loves working. I'd love to see her on tour, but unless she's doing small small venues, it would be a waste of time. She can tour in her 50's. She doesn't have that much time left to be 'relevant' in the mainstream's view.