Tobold has a post about whether not having a sub will hurt GW2.
In my opinion GW2 is likely to be a slow burner game, just like Guild Wars 1 has been. There’ll be the usual mad rush of MMO tourists that come and play the game exclusively and then leave. But also with no sub and the “buy to play” model for content it is a potentially great casual (or 2nd) game. As I’ve posted before, I’m not a “one game exclusive” type of player anymore. I like to mix it up between gaming sessions.
That could keep a lot more people actively involved in the game beyond the 3 month or 6 month periods. Players have been playing GW1 in large numbers for years with dwindling content releases. There have been campaigns added and free content patches but not huge updates since Eye of the North came out in 2007. So that’s 4 or 5 years without a major expansion. But the game is designed with relatively easy story content to consume, different classes to play (for altaholics); plus balanced PVP and a ton of serious PVE grinds for the more hardcore PVE players. Raiding doesn’t have to be the only activity for the longer term player. People have played the heck out of GW1 just to earn a title or to obtain a set of fancy looking armour that gives no better bonuses than the standard easy to get top tier armour!
So I think Guild Wars 2 has the potential to last well past the usual drop out timeframe. I doubt it’ll have collossal player numbers, but lets hope it lasts better than SWTOR! Some people will go check out Mists of Pandaria on the 25th Sept and so GW2 will see a concurrent login drop. I suspect they’ll follow the pretty standard pattern of blowing through the MoP content in 4-8 weeks and will then clicking un-sub again. In which case ArenaNet need only time a nice fat content release for late November or early December and they stand a good chance of tempting back some disaffected panda-players!