Isn't it mimed though?

http://www.youtube.com/watch?v=gXERQKvCObY&t=1m6s

So is this mimed or not?

he cant even be in tune while miming...

The group performances aren't mimed, they are live. So if he was out of tune, it was done live.

Is that new to this series? I was sure they were mimed before.

I'm pretty sure it's live because Dermot keeps introducing it with "Singing LIVE it's the XF finalists" etc.

Well if Demot Says so?

Though I agree it must be live in that the fact that they are some people who are so out of tune that you really can't fake that surely.