ALL PLAYERS THAT HAVE PURCHASED THE GAME RECEIVE FREE ACCESS TO CONQUEST UNTIL THE RELEASE OF GLOBAL AGENDA SANDSTORM LATER THIS YEAR.
You just get some months subscriptions for free, with the release of the addon it will end.

Erm, no, you have the pay for that but its a one off fee, it's like the guild wars model.
Unless they are contradicting their own website which said "It will stay subscription free, now and in the future."
Just found an email from them in my inbox coincidentally:
Players who buy Global Agenda can enjoy the game's current content in its entirety, including all existing PvP combat, PvE solo and co-op content, and AvA seasons, without a monthly subscription payment now or in the future. Future content updates will be delivered via optional paid expansions.
The first major expansion, Sandstorm, will be included for free to the entire Global Agenda community. To celebrate this change, the game is being offered for 33% off on Steam from now through July 5, as part of Steam's Summer Sale.