Thank you, Michiyo-
, A Pierrot's Aria
, and Mhacy
Original Japanese Twitter entry: (as posted above by kind members ^^)
"鋼フェス2011、第二弾出演声優発表！ 追加出演はリン役：宮野真守さん、グリード役：中村悠一さん、スカー役：三宅健太さん、メイ役：後藤麻衣さんの4名です。"My translation (the way I read it ^^): "Fullmetal Festival 2011, announcing the second wave of attending voice cast members! Additional attendees are: VAs of Ling (Mr. Miyano), Greed (Mr. Nakamura), Scar (Mr. Miyake), and May (Ms. Goto), total of 4 VAs."
So yeah, I could be wrong also, but so far I agree with Michiyo-
, and from the way this Twitt announcement is worded (note that it's stating that this is for FMA Festival 2011 at the beginning), it does sound like this is announcing VAs that are coming to the Festival.
(Of course, they could still be in "FMA:MiloStar" movie also ...although I'm still not sure if Xingese characters would be in the movie... I hope they do, but not sure... but as far as this announcement goes, it does sound like this is talking about VAs that are coming to the Festival.)