The Mid-Atlantic Sports Network (more affectionately known as MASN) has been a long-time HD holdout in the world of regional sports networks. After finally getting its act together and blessing viewers with some Orioles / Nationals games in high-def, the channel has announced today that it's fully ready to embrace this century. Beginning in March of 2009, it will launch a full-time HD channel and "more than double the number of HD telecasts of Nationals and Orioles games." Once live, it will air up to 200 MLB tilts next year in high-definition, and furthermore, it'll carry "Ravens preseason games, select NCAA Division I football, basketball, and lacrosse games, and ESPNews in HD." Also of note, we're already told that many of its current distributors will carry the 24/7 HD channel, including Comcast, Cox, RCN and DirecTV.