The obvious candidates from the sprinters this year are Cavendish, Sagan, and Greipel.
Cav is the lock for the green jersey. Lean, mean, and focused, he's frustrated from falling one point short in the Giro, and is coming into the Tour looking for intermediate sprint points. The green is about consistency in the sprint finishes and reaching intermediate sprints over initial climbs that the gorilla sprinters can't. Cav lost 4 kg before the Tour for this purpose.
For raw sprint wins, Cav's at a disadvantage this year. Sky's focused on the yellow, and with Cav's focus on staying light, he's not going to have the brute power a monster like Greipel has, or be conserving strength for the final like Sagan. So I don't expect the usual Cavendish domination this time.
Greipel has been a true monster in sprints this year, and I think he's the guy for the big sprints. Sagan was unbeatable in the Tour of California and races following, but he hasn't gone against Andre Greipel. So I expect Sagan will get a win or two, but Greipel more like three. Cavendish will win as well, but Greipel is the man for the raw sprint stages this year.