Moving one closer to the promised 100 HD channels, RCN has added MGM HD in Chicago. Previously noted as coming to DirecTV and FiOS, we're still waiting to see MGM's 4,100 movie-based channel and VOD platform on a few other providers, but ACE Communications, Antietam Cable and Armstrong Communications subscribers should have it soon. Meanwhile, RCN customers can feel comfort knowing that at least a small piece of the date-TBD 100 HD channel future, is now.