It was inevitable.

If you had one of those free weekend trials that you never got a chance to dust off, now's a good chance - the game is free to play up until level 15, effective immediately. Any previous free trials, free time accounts, or weekend pass accounts are all valid for this, and if you like the game up to the cap, you can upgrade to a full account to begin subscribing. A full FAQ explaining everything is located here, if you have more questions.