http://wccftech.com/microsoft-changes-services-agreement-xbox-now-requires-sign-every-5-years-maintain-gamertag/
Hopefully free up some dormant gamertags
In the Microsoft Account or Skype Account section, weve added a requirement that you must sign into the Xbox Services at least once in a 5-year period to keep the Xbox gamertag associated with your Microsoft account. Weve also added that if your account is compromised, we may be required to disable access to certain content
Hopefully free up some dormant gamertags