I discovered that you can import your favorite NeverWinterNights character from the NWN Official Campaign into the Shadows of Unrentide expansion. On a whim, I tried to take my old toon from NWN-OC into SoU, and it worked. I was able to continue the story with my little rogue.
I'm not sure if the same can be done for the Halls of the Underdark expansion pack, but I would be willing to assume that it can be done.
This is a really nice feature, considering that most players don't want to walk away from a character they have spent months developing.
If the Official Campaign might not be your cup of tea, you can always take a brand-spankin-new toon to the player-made server of your choice and start there. Fair warning though: if you start a new toon from scratch on a player-made server, and if you either eventually learn that you hate that server or find out that the server has died out, then your toon is lost for good. It might be better to take an old favorite toon to the server and check it out to see if it's to your liking before you invest months of your time.
I'm thinking that EverQuest2 will end up being pretty good. The peeps at Sony took a long, honest look at the flaws from EQLive, and they are going to do their best to deal with those problems in EQ2. No more cookie-cutter toons. No more unwanted/unneeded classes. Players will now have the ability to develop their toons, taking them down several career paths. And since all Tanks will be able to tank well, the holy Trinity of the Warrior, Healer, Enchanter will be a thing of the past. Druids and Mages will finally be able to find a place in the group.
One thing that bothers me is the fact that they left the group size at six. Why not expand to eight? Daoc did it, and it seemed to work well.