People saying no to this possible collaboration are just insecure. I mean this is just a freaking duet and a duet is meant to complement and not outshine each other. Producers thought of the right way to put Beyonce, Usher and Lil Wayne's voices on one record so there's gotta a be way also to mix Beyonce and Rihanna's vocal styles on one track. It's not like you only and always have to collaborate with artists of your calibre. Rihanna is a huge artist now for others to decline her. And Beyonce's discography is not all that peerless. Some of her songs are actually lackluster.