[Tom4784]

Well Take That & Westlife are pretty much a given. I can see Cher getting someone like Tinie Tempah or tinchy Strider or some other generic rapper. If the Christina Aguilera rumour is true I can see her performing with someone as well.

I think it'll be:

Cher & Tinchy Strider/Tinie Tempah/Generic Rapper.
Rebecca & Adele? (Probably not likely but Adele's got an album out next month and given the fact that X Factor has given her a boost in sales this year I think she might pop on for the exposure.)
One Direction & Westlife.
Matt Cardle & Christina Aguilera (if she is a guest next week) or more likely Take That