According to MLB.com's Mark Bowman, the Pirates have claimed Braves' OF Brandon Jones off of waivers (via MLBTR). Jones, who turned 26 in December, hit well in the minors despite a low OBP before running into some struggles at Triple-A and in limited chances with Atlanta in 2007, 2008, and 2009. John Sickels wrote positively about him last spring and prior to his recent struggles he was one of the Braves top prospects.
You can see his 2010 CHONE and Marcel projections at FanGraphs and his full minor league stats are here. There's no word on a corresponding move yet, but let's be serious here; Jones is an athletic corner outfielder with a good arm and a good defensive reputation that bats left-handed. Between him and Ryan Church, Brandon Moss's days as a Pirate seem very obviously numbered.
UPDATE (4:46): I want to say that I like this move, but word on the street (aka tweets from Jen Langosch and John Perrotto) is that Jones is only squeezed on to the 40-man roster because the Donnelly signing isn't official, while Rob Biertempfel cryptically says to "not get too attached" to Jones. Could be that he's going to be quickly flipped to another team in a trade before the Donnelly signing becomes official.
SECOND UPDATE (8:00): I just want to stress again how weird this situation seems. It's not the claim of Jones that's weird, but that the team went out of their way to point out that for whatever reason they briefly have a roster spot open. DK speculates that Jones may be a part of another deal that's soon to be completed with the goal of freeing up Dotel's roster spot. Whatever the case, something else is obviously about to happen.