Ehh if its free I'll try almost anything once.
Edit: Found this at the bottom of your link
Conditions
*The offer is only valid if you sign up a new Anarchy Online account between the 15th of December 2004 and 15th of January 2005. You can play free of charge until 1/1 2006. Should Funcom deem that a too high-increase in server load or other unforeseen events will lessen the experience for existing players the offer will be terminated at our discretion. The free version does not include access to any of the three expansion packs. Should you wish to upgrade to any of the expansion packs monthly subscription and client fees will be added.
In other words beware they might change thier minds.