These actors that may not be known that well, have bit parts, here and there
Sean Maher
He is best known as Simon Tam in the series "Firefly" and the movie Serenity. He has been Wedding Wars as John Stamos' boyfriend before he came out in real life. He has been in Make It or Break It and Arrow as Sharpnel. He's from New York and 39 years old, he came out in 2011. He most of the time plays 'perfect' guys.
Jonathan Bennett
He is famously rumored to date Matt Dallas (Kyle XY) who has recently came out. Jonathan is best known as Aaron in Mean Girls, Van Wilder in a prequel and Bo Duke in a Dukes of Hazard prequel. I don't think he has officially come out. Next up for him is The Out and Out, Mining for Ruby, and Submerged. He's 33.
Jonathan Chase
35 year-old actor best known as Jarod in Another Gay Movie and rumored to date Anderson Cooper. I don't know he officially came out as well. He played Sam in Tyler Perry's "Love Thy Neighbor" as a Neil Patrick Harris' Barney-like character. He has also been in Bones, Victorious, Shake It Up, Monk, and Chemistry.
35 year-old actor best known as Jarod in Another Gay Movie and rumored to date Anderson Cooper. I don't know he officially came out as well. He played Sam in Tyler Perry's "Love Thy Neighbor" as a Neil Patrick Harris' Barney-like character. He has also been in Bones, Victorious, Shake It Up, Monk, and Chemistry.
Matt Dallas
31 year-old actor I mentioned before, he did come out and he is best known for Kyle XY. He came out in 2013 when he announced his fiancé. He has also been in Baby Daddy, Anne & Jake, Eastwick.
Adam Rikaart
37 year-old actor best known for Young and the Restless, he came out recently.
There is also Matt Bomer (White Collar, Magic Mike), Jim Parsons (Big Bang Theory) and Zachary Quinto (Star Trek, Heroes) but I think they are well known now. They all came out already.
Related: http://spanengrish.blogspot.com/2013/03/im-not-gay-but-my-brother-is-celebrity.html | http://spanengrish.blogspot.com/2009/12/out-celebrities-and-where-they-are-now.html