^ We don't know. Nothing is confirmed, as far as I can tell. The wording on some articles could be taken either way (performing+ presenting or just presenting), so when other news peeps went to do their write up, they used their own words and may have read it the wrong way... and then others followed suit.
She is certainly confirmed as a presenter or whatever they do.. read out noms... time will tell. Maybe Katy will tweet with more info or something, LOL!