Whenever I hear someone complaining about how they'd like to play an MMO without the monthly fees, I usually try to get them to try out one of the hundreds of free to play MMOs out there, if only to eventually lure them over to the high quality subscription games that await them on the other side. In this way, a solid tactic being employed by many MMO development companies is to simply look at what's popular in the pay to play world, and then try to emulate it as a free to play MMO. Runes of Magic is a good example here, in that, despite the fact that it has some unique features that set it apart from World of Warcraft, it is still considered, by and large, to be a free to play spiritual cousin to the subscription based behemoth.
While I certainly have nothing against these F2P adaptations of successful MMOs, I'll admit that the first thing that entered my mind when I started up Shaiya Online was that the game has a lot of that Lineage II flavour, albeit a little bit less developed in comparison to its pay to play cousin.