After Wellens going AWOL yesterday, I should probably keep quiet (OK, I didn't think he'd destroy the field, but I thought he would at least try to make a selection).
Anyway, there are obviously three main players
BMC - Yesterday was their dream scenario. The break snapped up all the bonuses. Hence, for someone else to win Dennis will have to be dropped (I can't see him losing the race on the final climb, it's too short). BMC have other cards to play, but Phinney won't be stronger than Dennis and Quinziato and GvA are behind Sagan (and Martin), so BMC will definitely play the Riders of Rohan today, with plan B (and this would be a really bad case scenario) being opportunism and a sprint up the final climb by GvA.
Etixx - Will certainly miss Tom today, but they have a number of cards to play. They've got 5 guys within a minute of Dennis, so they'll use the numbers game and try and send people on medium-range attacks. I expect Stybar and/or Trentin to attack on the penultimate circuit, with Martin or (more likely) Terpstra counterattacking. However, as well as dropping Dennis, they need to deal with Sagan.
Sagan - I think his best hope for an overall victory lies in Etixx starting to play the numbers game relatively early, forcing BMC to control. Sagan should ignore the early moves and hit hard on the final circuit, but it's a huge call.