Here's an interesting article at the Altoona Curve's website in which Kyle Stark talks about what Altoona's roster might look like next year. So, to piece together what's in the article and combine it with some educated guessing (WTM's minor league camp roster and depth chart are invaluable) here's what might happen at Altoona. A lot could happen in the next couple weeks, and much depends upon factors that are unknown to me, so this is mostly just for fun for now:
CATCHER: Kris Watts. Watts hit well for Lynchburg last year but isn't a prospect. Tony Sanchez will probably start the year with Bradenton, and Watts won't be much of an obstacle if he needs to move up.
FIRST BASE: Miles Durham is mentioned in the article, but Matt Hague is also a possibility, with Durham potentially getting playing time in a thin outfield. Neither are worth getting worked up over, but 2009 was Hague's first full pro season, so there theoretically could be upside there.
SECOND BASE: Josh Harrison was acquired in the John Grabow trade, and like everyone else in that deal, he's had a miserable time since joining the organization. But he's still just 22 and has enough contact ability to be somewhat interesting. The article also mentions Jim Negrych and Jose de los Santos, neither of whom are prospects at this point.
SHORTSTOP / THIRD BASE: Chase D'Arnaud will be the primary shortstop, and Jordy Mercer will probably play third most of the time. The article doesn't mention Kevin Melillo, acquired as a minor league free agent this year, but he's probably a good bet to play third--with Mercer moving to short--if D'Arnaud has a day off. Melillo is also capable of playing at AAA, but Indianapolis already has a ton of infielders.
OUTFIELD: In addition to Durham, there's also minor league free agent Anthony Norman and former Red Sox prospect Jeff Corsaletti. The article doesn't mention this, but Gorkys Hernandez was assigned to Altoona when he was cut from big league camp, so one would think it would be possible he'd start the season as their center fielder.
ROTATION: Tim Alderson, Justin Wilson and Jeff Locke look awfully likely. Rudy Owens is mentioned in the article but could be in either Altoona or Bradenton; he only had a handful of starts in Class A+ last year, so I see no reason to rush him. Tony Watson isn't mentioned in the article, but I think he could be in the Altoona rotation anyway. Nathan Adcock, one of the pitchers acquired in the Jack Wilson deal, played in Class A+ all of last year but isn't old and wasn't spectacular; he isn't mentioned in the article, and I wouldn't be surprised if the Pirates just sent him to Bradenton. Michael Crotta and Kyle Bloom could fill out the back of the rotation if there aren't enough prospects to start the season. Matt McSwain is also mentioned in the article, but the scuttlebutt from the message boards is that he has retired; I haven't seen a reputable news service confirm that, though, so take it with a grain of salt for now.
RELIEVERS: Ron Uviedo and Ramon Aguero will almost certainly be at Altoona. Michael Dubee, Harrison Bishop and Tom Boleska are good bets as well. Beyond that, it's tough to speculate, since much depends on what happens with the starting pitchers. Dustin Molleken, Derek Hankins and Jared Hughes could all fit in somewhere. In the article, Stark also mentions Daniel Moskos as a possibility, even though he pitched at Altoona all of last season without embarrassing himself (or playing particularly well). That would pretty much be the nail in the coffin of his reputation as a prospect if he were sent back.
UPDATE: I just saw that the Altoona Mirror has also taken a guess at the makeup of the roster.