From Tim and confirmed by the Charleston Daily Mail.
Zack Von Rosenberg
The first four of those guys will be the main starters, with Fuesser and Benedict fighting it out for the sixth slot.
There's obviously a ton of upside in both the pitching staff and the lineup, but the prominence of likely organizational players, especially among the hitters, is also interesting. Singer (third base) and Lashmet (DH) are currently slated for starting roles, while younger, more interesting players like Carvajal and Avila will start the year on the bench.
Von Rosenberg and Fuesser are back in West Virginia (and so is Dodson, although he missed part of 2011). It looks like the Pirates don't regard Fuesser as much of a prospect, despite strong numbers. Tim notes that the Fuesser/Benedict rotation spot is likely just a placeholder for Ryan Hafner, who's recovering from injury.
In any case, Bell, Kingham, Allie, Hanson, Osuna, Dodson, Garcia and Polanco should make the Power a lot of fun to follow this year.