I totally agree with the OP. Little Mix, Misha and Janet are all pretty relevant. With the right songs and marketing I think all three acts can be successful after the show. I didn't like Cher and wasn't a massive fan of One Direction, but it doesn't surprise me both got record contracts and are doing quite well at the moment. (I also believe both Matt and Rebecca will find their niches as album artists rather than targeting the singles markets.)
This year I can see Misha and Little Mix, with some decent original tracks, having some success in the singles markets. For Janet, who I believe is a long way from perfect, I think there is a market out there for her. The folk sound is 'in.' I don't believe Janet is anywhere near as talent as other artists with that sound however, again, with the right marketing she could have some success and therefore will probably be offered a recording contract.
As far as the other three go, they all have great voices, so it wouldn't be a surprise if any of them got a contract. I suppose Amelia is the most likely to be successful. A lazy comparison would be Kelly Clarkson. I do think she's less likely to storm the charts than Misha B and Little Mix, but who knows what kind of music will be dominating the charts in a year?
Marcus. I love the voice, the performances are great and he seems like a really nice guy. I don't see where he is as an artist. Post- Bruno Mars performance, we're supposed to believe he has found his niche. I'm not sure. I don't think his sound will translate well into sales, therefore I feel he'd probably need to win to be guaranteed a contract.
Craig is a difficult one. I find him dreadfully boring but I can admit he has a nice voice. I can definitely see someone seeing potential in him, giving him a one album of covers recording contract and ditching him after the Mothers' Day sales. Commercially, I can't really see him having much success.