This would be similar to getting 400 favor points to unlock the drow player character or collecting so many points to get veteran status.
But after reaching a high level say 15th level or above and collecting so many favor points either with the server(i.e Aronnessen) or maybe collecting so many favor points with a certain "house". The players account is rewarded with so many square acres of land to build whatever the character wants. Castle, dungeon, ruins, church, small town, farm, just forest land, tree house etc.
Of course Turbine would have to allow the players access to the entire continent to roam in order to have so many square acres. But after achieving high levels I would like to see something more for a player to do with his/her account.
I know that we will be getting airships for guilds but the ships I would guess will be controlled by the guild leader and maybe the officers but for the rest they only have the privilege of using it even though they themselves will have helped to get it.
We as players should get something to design and work on.
Maybe we could just buy lands from the game nobles and start building.