Kwiatkowski one tried to go for the GC and it was at 2013 Tour. He almost got 10th and was white for a quite long time, but he lost his top 10 spot to Navarro after a breakaway on stage 19 if my memory is correct. Also, i think he will be more focused on the WC. However, i also remember there was a minor hype for JJ Cobo before 2011's Vuelta and i myself thought he would have a lower top 10. The same was for Hesjedal before Giro 2012 so i guess anything can happen.
If there's no clear favourite, then it'll be similar to 2010 Vuelta with this time Peio Bilbao either crashing out or doing a Simon Yates and Nibali will win in the end while showing nothing, because he's one hell of a lucky bastard (2010, 2016, i'm excluding 2014 because then he was probably in the form of his life). Majka (if he rides) will get 3rd place, while being glued to someone's wheels.
If there's no clear favourite, then it'll be similar to 2010 Vuelta with this time Peio Bilbao either crashing out or doing a Simon Yates and Nibali will win in the end while showing nothing, because he's one hell of a lucky bastard (2010, 2016, i'm excluding 2014 because then he was probably in the form of his life). Majka (if he rides) will get 3rd place, while being glued to someone's wheels.