The first thing that needs to be said is that Guild Wars is not an MMO. There's a lot of misunderstanding going around, but GW is an online RPG that blends elements from Diablo-style online multiplayer, while integrating some MMO elements. The cities and certain dungeon entrances are basically hubs, but once you exit those areas for the wide expanses of desert, rolling hills, and snowy mountains, you'll be flying solo, most of the time. You can teleport instantly back to a town, even during combat, which is nice. And you can also log off at any point. It's kind of annoying to watch yourself die as you answer the phone or go to answer the door, and GW gets rid of this. When you log back on, however, you'll be back at one of the hubs, where people mill around, doing the typical MMO thing--chatting, emoting, and trading.