Barring injury or unforeseen circumstances, and going on current form, think Natalie will win. Of course, one (or more) of the others might have a massive breakthrough, but at the moment it's difficult to see that happening - at least on the scale needed to become a realistic threat. Even given the flak she's had about her dance background, she's not such a divisive character as Denise and is quietly flying more or less under the radar. And Artem has a pretty big fanbase himself - which ain't gonna hurt!
I doubt that anyone could have stopped the post-Olympics Louis Smith bandwagon last year (including Natalie). But if, as we're led to believe, DVO came second despite all the negative publicity she attracted, I think a Natalie win is a dead cert.
Just reaching the final is actually the real competition for the others.