Could be a great race. Cancellara is the favorite, but not by a huge margin. He didn't look as strong this year as he did last year in the Ronde, and last year he had a lot of trouble winning Roubaix.
On the other hand, he could be having a different build up. Last year he looked past his peak in Roubaix, while this year he improved a lot between Strade Bianchi, where he looked fairly weak, till now. Maybe he'll be stronger next week.
Although I think Cancellara is the favorite, I'd like Vanmarcke to win a little more. Great gutsy rider. He has had a lot of bad luck the last couple of years, but when he is strong, he is really strong.