We will need to wait till next summer. Dumoulin won't be joining Froome and Aru at the Vuelta this fall. Bummer. I do think that Aru can take down Froome at the Vuelta with 5 summit stages, 8 hill stages a TTT and a short time trial only. Contador will be there too. Should be fun in Spain. It's not "taking down Froome" in the sense it is not the TdF, but good enough for me, and I like the racing at the Vuelta better in terms of format and stages.

sure

Really need to first see in October what ASO comes up with for the 2018 tour.

Interestingly enough, the Sky team tactics actually work out really well for Dumoulin. Just setting tempo pace so high up the climbs that people can't attack. That's Tom's bread and butter. Hang on there then beat Froome in the TTs.

certainly he is the man who could beat froome at his own game - taking time in the TTs and riding steady in the mountains. i suspect it might take a couple of attempts though, mind you he nearly won the vuelta without even intending to try and won the giro in his first actual attempt at gc against a pretty strong field so he's not far off right from the start

the interesting thing is that the TdF has moved to create "anti-froome" courses with low TT kms which works against dumoulin even more so. a course like 2012 would be a great contest between froome and dumoulin, though likely not a very exciting one