You might want to include more information either somewhere on your main page or during the signup process. I got halfway through registering for the "free" trial when I was asked for my billing information. No mention of this anywhere (and I scoured your webpage pretty thoroughly). Having played other MMOs, I am guessing you need this information to set up the account, which will be billed at the end of the 14 days unless cancelled. However, this is not stated anywhere, and turns me off from wanting to enter my credit card info for who knows what kind of hidden charges.
People new to MMOs in general will almost certainly not be inclined to do this, having had no warning that they would be charged for anything and suddenly seeing a request for their credit card info. I'm not suggesting you change whatever your system here is, just that you provide more information. Much as I'd love to check Horizons out, I'm certainly not going to do it without knowing exactly what I will be billed for and if I will need to cancel my account or what if I decide not to accept the charges.