Ctb is completely correct on this. As it seems '# of Accounts activated' is units sold, this information can't be used to determine anything other than number of units activated. Not number of players, either total or currently active, as we don't have a breakdown on how many campaigns/expansion each REAL account has; not how many REAL accounts each person might have; not how many people are still playing; if the player base is declining; and so on. NCSoft & Arenanet do have this information but, understandably, are keeping it to themselves for competitive reasons. All it tells us is units activated. That is it, nothing else.
Also, unlike some companies that are apparently including trial accounts, units shipped, etc., these are actual numbers of campaigns / expansion activated (my assumption based on the term 'activated'), not just the total production run, or those sold to distributors or retailers, which again, is what some other companies may use in their 'sales' figures. This should also mean both the Trilogy and Complete Collection packages only count as 1 unit.
Using NCSoft's numbers clearly shows 2008 sales were considerably less than 2007. This is to be expected as there was new content sold in 2007, nothing new in 2008, just repackaging of various types.
4Q 2006: 675,000
1Q 2007: 433,000
2Q 2007: 362,000
3Q 2007: 583,000
4Q 2007: 378,000
Total 2007: 1,756,000
1Q 2008: 281,000
2Q 2008: 218,000
3Q 2008: 212,000
4Q 2008: 214,000
Total 2008: 925,000
So you can look at things either half full or half empty. Sales through 2008 were steady and I see that as pretty good considering nothing new was released. 2009 should probably see an overall decrease in units sold and that is what NCSoft is projecting, at least Sales/Operating income 2009 15,000 min/max compared to 2008's 23,227; in million Kr Won, consolidated - including currency exchange rates, so that isn't real useful as it depends on money exchange rates more than anything, but does show a downward trend. That is natural as without new content for sale increased sales are very unlikely, especially considering the age of the game. You can also view those numbers as "OMG, the Game Iz Ded" if you like. Depends on what you consider dead or doing well. That is strictly opinion, either way.
Is GW a success? Yes, clearly it is and I don't see anyone really saying it isn't. Are sales declining? Certainly, that is a fact and expected with no new content for sale. Does GW have a larger active player base than most or many other MMO games? Probably, but we don't really know. With new people coming in at steady, if slowly declining rate, some people coming back, some leaving, no one other than Arenanet really knows. Are less people playing now than back in 2007? Very probably, but only Arenanet really know the actual facts, everything else is personal opinion. I've been in an outpost that was packed one minute then a few minutes later emptied as everyone went out to do stuff, then someone comes in and says, "this game is SO dead", then they leave and 5 minutes later the outpost is full again. I've been in outposts that are empty and stay that way the whole time I'm there. Other times I see someone map in and say "this place is packed, I've never seen so many people here", yet I thought is was fairly empty compared to most other times I've been there. It is all relative.
As long as you are having a good time doing things you are probably in the "doing fine" category; those that are bored most likely fall in the "OMG, Iz Ded" range.
In the long term, it is just a game. The only people that really have a major stake in GW are the people working for ArenaNet & NCSoft, and the shareholders. Let them stress about things. Either have fun playing or go do something else and check back now and then. GW2 will be out when it comes out. If it never comes out life will go on (or not, for those 2012 doomsday types
). The nice thing about GW is that it doesn't depend on a monthly subscription and operation costs are pretty low thanks to some good game design and programming; and that GW1 sold a bunch and it is very likely GW2 will be released at some point. In the meantime, go have fun playing GW1 or whatever else you like.