Contador has lacked "spark" all season. We saw that in the first races of the season, both in Spain and Italy and then at the Giro he never put in a dominating performance in the mountains. Given his ride on the Mur de Huy there isn't anything to make us think that he can hang with Froome today, who, by contrast, is obviously on 2013 level.
Having said that, I can't imagine that Contador at all plans to go through another 2013 humiliation (how else can it be called?). Here, then, is where the enigma lies, since all indications don't lead to a vote of confidence, yet he may have planned to ride into top shape for the mountains. If this is the case then he will have to perform to that today, which means arriving with Froome or loosing very little time.
Today he will be forced to lay his cards on the table, so we will see what hand he really has. If Froome drops him from several ks out, then its over. If Contador is able to stay with him more or less to the finish, the he's still got a fighting chance in my opinion.
PS. As to Electress' thoughts about Sky, being smug is never a way to win my sympathy so I can relate to your sentiments. All the more so when done without compunction, but I can't say any more than that here as it's for the clinic.