Matt and Gareth for definite, plus whichever other one decides to do the most improving and has a decent public vote behind them. I think that's a toss-up between Shayne, Luke and Oona right now.
Controversially I'm going to say Beth will go out in the semi because while clearly very nice and with all the raw materials to do well, she has always come across as deeply, DEEPLY dull for me in every media situation. I'm just not sure she has the personality either on or off the ice to get her scores and votes up past those with a bit more pizzazz.