I really wish Mariah would include that Janet duet on her next album

and a Céline duet as a tribute to Whitney. An Alicia duet would be nice too. Maybe a Bruno Mars collaboration as well and Mary J Blige, maybe Justin Bieber to get the teens... Rodney Jerkins aka Darkchild as a producer (I know he produced atleast one song for her new album already), and maybe Stargate and Calvin Harris would be cool. We need that #1.
I've always wanted a Mariah Carey/Dolly Parton duet, but that will never happen.