If Brian has genuinely cut all ties with BB then he won't attend the final. However I can't see him missing the chance to get his mug on TV again, especially on such a bit night, so he may come out with some old guff about being contractually obliged to be there or something. I dunno though, we'll see.
As for the rest, they will all be too busy trying to big up their part to engage in any feuds, they're all fame hungry at heart. I fully expect Twitter to be the battleground for their silly little spats for the next few weeks though...oh joy..