One of the best looking MMOs that's coming out within the next year or so seems to be Star Wars: The Old Republic.
I played Star Wars Galaxies for about a year or so but it didn't live up to my expectations at all so away I went. However, I do think there were several positive aspects of the game. This seems to be a similar, but much better version of SWG and hopefully it will have less headache in it as well.
There are many trailers to watch and a lot of info about it over at http://www.swtor.com and you can even sign up to be a beta tester there. While watching one of the E3 videos featuring Dallas Dickinson's commentary, he explained a lot about the online partying system, battle system, character progression and dialogue during quests. You can even 'teleport' back to the last place you bound yourself to (ie. a specific outpost, city, etc) after finishing a quest deep in a monster's lair, for example.
From what I saw during the E3 video trailer it looks pretty awesome.
All hail to MMO awesomeness!!