My money would be on Blue and I don't really have a close 2nd. He is in a spot where he can be brought on slowly, but also doesn't have much competition in front of him so I bet by mid season he is the primary back. With his natural athletic ability he is going to rip off a few chunk plays by accident.
I like Booker, but the bar for an OL to show their impact is going to be higher and tougher than it is for a skill player, which is why they dont win rookie of the year. EDGE players typically take some time to adjust to the NFL game, plus ours has no shortage of competition for snaps. Revel has the talent, but is likely to be behind the rest of the guys this year due to the injury.