I will be playing a neutral character (if I see he will be in disadvantage, I\'ll probably drive him to evil a bit) so I have thought about this for a while. Aelya is right, evil characters would not gain respect (like good characters), but the citizens will fear them and thus give them certain benefits only to protect their own lives.
Now...neutral characters are a bit harder, since their actions are neither good or evil. They should be able to go on both good and evil quests (but there should be some quests available only to those who align themselves to good or evil, I will explain this later). Now, neutral characters are very unpredictable, since they can go to one or the other side. The benefits should be, then, not as extreme as in a good or evil characters.
What I mean is, the discounts are not that big (they still get some discount, only because they look strong/dangerous), but they may get them from both evil and good NPCs. Evil characters would get penalites with good alligned NPCs (priests, paladins, clerics and the like) and, on the other hand, good characters would get penalties with evil alligned NPCs (assassins, thieves, criminals, etc). Neutral characters would get slight benefits from both types of NPCs, but should not be able to take full advantage of the interaction options.
Let\'s see if I can explain myself better with an example. We got a Paladin, a neutral Fighter and an Assassin travelling together. If they come across an NPC priest, the assassin would have a hard time talking to him, and would not get any benefits from the NPC. The fighter would get only some of the options, perhaps healing or getting a simple/average quest. The Paladin would get the most out of the NPC due to his allignment. The priest would offer services, lifting a curse, casting a holy spell on him, or perhaps he could give him a special quest (for being alligned to good in an extreme degree, he would get a quest that only this kinds of character have the chance to do).
If they come across, let\'s say, an NPC bandit, the Paladin would probably be attacked, or would they not interact at all. The fighter would have the option to capture him or kill him, but he could also get some information out of the bandit or buy some of his treasures. The evil character can betray this evil alligned character by capturing him or attacking him, or perhaps he could make him join the party for a short period of time (plus the chance to buy something from the NPC).
So, while being a good or an evil character will have benefits and penalties, neutral will receive a little of both. They will get smaller discounts and the possibility of interacting with a good or evil NPC, but not at the same degree than other characters.
That is what I think of the subject (I hope everybody understood what I meant), I\'ll be waiting for your opinions