I think probably best to wait for Warhammer Online - looks the most sand-boxish game to me. ALthough I dont really understand/like the Lore.
AoC should have some cool lore and a few people like it.
But really I agree with Billy - LOTRO seems to still have the most active content and bug free gaming exxperience. You can craft, buy a house etc etc
ANd there is endgame pvp area also [which is where I am playign all the time now as an Uruk]