i will keep it simple
first server - long lasting world, hard siege mechanics and current combat, maybe removed stat caps
second server - world wipe every 2-3 months, something changed in the core mechanics each world wipe, faster paced gameplay, current siege mechanics or a bit changed,the new combat, perhaps a smaller world, maybe something done with stat caps
The first server will be mainly played by people who like the crafting / building aspect of the game and the people that don't get bored of the current end game and they don't want to get their fun ruined by some pvpers or whatever with easy effort. people wont get raided by easy and cheap raids and their fun ruined.
The second server will be mainly played by players who doesn't like the current end game, loves the world beginngs/wipes, loves pvp competitive gameplay and the people that could hop in any time with others in a fresh new world anytime pretty much.
i don't like to play the current game, i only love to play it only when theres a new world - the hype, the rush, the new landscapes, starting out fresh, etc... the game really gets stall like 3 months in the world when you reach the endgame features and makes people quit the game because of the same old shit to just wait until a new fresh world, i would play on the second server.
the only downside to this i see is that the population gets divided between the servers, but its for the sake of fun