You mustn't underestimate a player who's rising in the rankings, has beaten Bartoli + Kirilenko this tournament and was just 1 game from beating Caro at IW earlier this year. Even so, Caro is the favorite in my eyes. She clearly has a mental edge over Sofia, it's very difficult to hit through Caro on a fairly slow HC surface like this and frustrating not-quite-top-players into not playing their best is one of Caro's specialties.
NB: Sofia has really tightened up her physique this season. She has actually become a bit of a hottie!