Usher and...?

Last night, Usher took to Twitter to announce some details of an up and coming duet... 

"YO WHAT UP NY!!...I bet you'd never guess who I'm in the studio wit right now? A Clue. Borough starts wit a B! The record is CRAZY!!"

 WHO IS IT?!? Not that we have a burning desire to know, (We aren't found of Usher) but 
with a bit of logical thinking, it's easy enough to guess it's Beyonce who has been in New York for some shows. It could also be Britney who flew from Toronto to New York in the last day for some ludicrous remix aimed to push mediocre singles to number 1? But your guess is as good as ours. Tell us your thoughts below!