Obvious favourites are:

Pop Idol Collaboration War is over
Gary Jules Mad world
UB40 and their Swing Low
Darkness Bell Ends
Bill Nighy (?maybe) Xmas is all around
Noddy??!!
Avid Merrion Proper Crimbo

I have my money on (literally) Gary Jules.

I wish i could forget that Alex bird from Fame Ac...

I really like Mad World but obviously I prefer Darkness and I reckon they have a better chance.

I suppose we should never rule out Cliff Richard