Beyonce, Lady Gaga and Britney will Stay for sure.
Lady Gaga is still young and I believe that ARTPOP era will end only in early 2015 and then she'll have her next album by 2017 so she'll be here.
also Beyonce, Her next album will be here in early 2014 and her era won't end till early 2015, she may will take a break after her fifth album, but I believe she'll than will make a BIG comeback. BookMark Me, sis
about Britney - I believe she's gonna take a LONG break after this Album, but There will defeintly be Album 9 and It will be a New, Mature Britney cause she won't be captivited to Jive records anymore. Maybe she'll try some other geners, Like Indie-pop or R&B, IDK.
But I Promise this - The REAL Trinity is here to Stay.