This isn't so much a mountain stage as a prelude to one. Today is similar to stage 14 with enough climbs to work up a sweat but not to blow up the race. Between the two stages the peloton will have done about 330km and a dozen climbs. This is all about softening up the legs for Monday. I dunno if this will undo the top guys, but it is sure to cut into the reserves a bit... if the pace stays high at all.
Anyway, the finish is not uphill today, so don't look for DiLuca's boys on the front. With Cavendish out and enough hills on the course to spit out some of the other sprinters, this stage is thoroughly up in the air. But as far as the GC is concerned it shouldn't have much effect. That part comes tomorrow. Enjoy!