2NE1 frontwoman and soon to be solo artiste CL has been working with will.i.am and the Black Eyed Peas on their forthcoming twentieth anniversary album thing.
We know this because she popped this picture with Taboo on her Instagram and included lots of hashtags:
And then there was this picture of her with will.i.am in a studio environment:
Fergie talked about a Black Eyes Peas twentieth anniversary thing here and mentioned she might not be involved mainly because she wasn't in the band at the very start etc.