Be at least 18 years of age

Possess a Square Enix ID account (Register for a Square Enix ID account here, if you don't have one already)

Possess an internet connection

Be capable of downloading large amounts of data

Be capable of submitting bug reports in either Japanese, English, French, or German

Like any other beta test, there will be several waves and opportunities to enter the beta so don't be discouraged if you don't make it in initially. For those looking for the PS3 experience, it seems that will be revealed "at a later date." Despite that, 2010 is going to be the year for this game's release, and I, for one, am excited. I may even forget about getting mauled by bunnies in Final Fantasy XI. More information concerning the title can be found on the Square Enix Support Center site for the game as well as the official site. Go forth and apply!