New server is definitely a no-no. It would probably raise the overall player base, but:
a) the old server would die out (Many would switch, even if it's just to give it a try which would cause a domino effect on other players)
b) the new server wouldn't last as long as you'd think, leading to an even more inactive player base than the old one
Why? Well, although it's true that people may be unmotivated by the current state of this server (people are high level, "ubergemmed" and so on), those who give up before they try, or after they try very little, here, would give up on the new server as well.
Vanilla simply isn't for everyone, and honestly, just like some others already said, it would be easier to progress here, than on a new server. Economy is stable, there's plenty of things to do for money, likewise, plenty of things to buy for money. So, sure, there would be people who would give it a try because "omg fresh start" hype, including people who quit this server, got banned and what not, but how many of them would stay is quite relative.
As for the WoW comparison, it's pretty unfair to compare two games and their numbers like that. Above all, what does "2k players" mean? Nothing without context.
In WoW - sufficient player base?
In a ToP server - too many players
In some other MMO - too few players
It's very relative and it's not a great source of conclusions. Moreover, saying that some strategy worked for WoW, doesn't mean it would work for ToP. Granted I haven't played WoW, doesn't take a game veteran to know there's a big difference between managing the two.
As for the "unhealthy, 2-side" PK people are mentioning, that's simply wrong. To someone not in it, it may seem like it's just 2 same groups of players fighting, but it's quite dynamic. Old people quit, a lot of new people join, guild dramas happen weekly, people split, people change sides. So no, it's not two sides fighting a holy war which rages on for decades, there's quite a lot of changes to the setup of both guilds on a weekly (sometimes even daily) basis.
To conclude, there's better ways of solving the lack of new players than a new server. But overall, it's a topic that's pretty difficult to address, because ToP is an old game which is flawed in its very core, hence it's difficult to get new players which would stay. (Who cares about those who simply take a look at the server and quit after a few minutes/hours/days - which would be a large part of the players playing the new server).
Source(s):
-Trust me dude
-Playing this server since day 1 and having played dozens of servers which tried similar stunts/strategies and simply failed.
