Uh oh, this one is difficult. The assumption is, that none of the top GC contenders have bad luck, crash, injury or illness. Which is quite hypothetical.
The battle for the overall win, I suspect will be between Froome and Contador, they'll sit on each other. Spoonwise. When the battles go on, they're plenty times above limit, so I suspect the loser of them not to be second.
And the loser will be Contador.
I figure that, since every of his competitors knows he is in lack of time to hit a second peak after Il Giro. So they will take advantage of that and put maximum stress on Contador and Tinkoff-Saxo. I suspect both Astana, Sky, Movistar to start the first week with a handfull of grenades. Just to shake Berto.
In the second week, I suspect the first real mountain stage to explode and reveal Froome and Contador to be a level up upon Quintana, Nibali and Valverde.
Albertos nature is not conservative rides. He will suffer from that with the pressure from Sky, Astana and Movistar.
Hence, with no ilness, chute, bad luck, the GC in Paris will be something like this:
1. Froome
2. Valverde +3m
3. Quintana +3m
4. Nibali +4m
5. Contador +5m