If Beyonce performs, she will be the most talked about DURING the night.
Regardless if Britney sucks, the tribute sucks, she doesn't actually receive anything, or the opposite of all that (everything goes well, etc)- the press will be on her like a pack of hyenas with all the articles about her the next day.
Gaga will fall flat if she performs Born This Way Edge Of Glory You & I ANY of her singles from this era because so far none of her performances from this era, while good, have been "talk-of-the-night" worthy, tbqh.
Pretentious twats will talk about how Adele was the saviour of the night & the only good performance.
Katy Perry will be the most talked about on forums if she wins VOTY or any award over Gaga, increasing the amount of hate just like all the other times over stupid awards (like Kids Choice Awards and ****).
I don't think Adele or Katy will be really the talk of the night outside of forums, it seems like the Britney tribute was added in to pull the actual ratings. So this night will be about what's actually happening as opposed to Brit/Gaga/Bey stans all arguing over who deserved which VMA, kind of like the recent Billboard Awards.
Overall, it will be a great night.