Quarterback:
Like: An in his prime franchise quality quarterback. What's not to like about that? If anything Haley is going to make Ben better. I'll virtually guarantee the new offense wont make Ben worse. Both he and Haley have much to prove to the world and both know the key to any current and/ or possible future success they respectively have lies with working well together to make this offense special.
Both Byron Leftwich and Charlie Batch are competent reserves, who can get the Steelers through a short stretch without disaster if needed.
Fear: Injury to Ben. While Leftwich and Batch are competent back-ups, neither are close to Ben. The Steelers can win games without Ben. But have no chance to make a serious run at the Super Bowl without a healthy Roethlisberger.
Bottom line: I think Ben and the offense will have a huge year.
Running back:
Like: I think Isaac Redman is underrated, and I think he was easily the Steelers best running back in 2011, so I think the fears that we'll have no running game without Mendenhall are misplaced.
Between Barron Batch and Jonathan Dwyer I think one will emerge to provide adequate depth until Mendenhall comes back off the PUP list.
I'm really looking forward to seeing how much they use Chris Rainey in the preseason. Rainey could be the wildcard in our offense that could spark them on to special things. The big question for the young backs of course will be whether they can pick up blitzers when called upon? Whoever eventually fills the role of 3rd down back will have to prove able in this area.
I also think a fast start by Redman could spur Rashard Mendenhall on to greater heights when he comes back. Mendenhall's coming up on a contract year. He needs to improve greatly off last season if he's to have any chance to get big money.
Fear: Fumbles by Redman, and no one emerging as a quality 3rd down back due to a collective inability to block.
The perfect solution would be to make Mendenhall the 3rd down back when he comes off the PUP list. But I doubt his ego would allow for it. Anyway I think Mendy has been underutilized as a receiver. He's got above average hands and is a quality open field runner once he cathces the ball. His blocking is at least adequate, so Ben wouldn't be a sitting duck back there.
I think you could sell Mendy on being the 3rd down back if you promised him split duty with Redman ( or close to it) on 1st and 2nd downs. He could still get around 15-25 touches per game this way. 12-15 carries with 3-6 catches a game would be perfect for Mendy imo.
Botom line: Redman is a perfect between the tackles running back if he holds on to the ball. Mendenhall needs to play well for his next contract. Rainey could provide fireworks as a change of pace back. I think what many see as an area of concern will prove to be a quality unit.