As you all may know 1.8 has not been revealed to when it's coming out but they are thinking about including name changes. I just wanted to inform you that if this ever proceeds and Mojang add it my IGN will be: HeyItsSev or Sev_
You can check to see if a username has already been registered here - https://woodycraft.net/threads/minecraft-name-checker.33744/ or https://www.doctormckay.com/utilities/mc_checker.php