It's actually a really long list because i really want to see if Jones and Hightower are going to take a big next step, I want to see Kelly beside Wilfork, and I want to see if a Talib/Dennard CB pairing is significantly better than what we have seen in recent years.
Offensively the 2 who i really want to see are Vereen and Boyce, who I actually think is going to be the rookie WR who ends up having the best season. I really expect Vereen to have a big year and offset the loss of the murderer. I also want to see if Ridley is going to turn into a dominant RB.
Overall I think this is the most interesting team we have gone into a season with in a long long time, there are tons of questions and plenty of talent to answer them, should be fun to watch them develop.