Will it be possible for players to become evil and for NPC to react accordingly?

You probably won't be able to be an evil bad guy, but you can probably be an A-hole, and NPC's might react to that.

Probably this. Would be nice to have opportunities to affect your status with certain groups of NPCs based on in-game choices.

id like to be able to set my alignment to evil caotic or something similar to that effect.

This isn't Fable Online.

However, once a crime system is in place, if you go around murdering people, I'm sure the guards will start treating you poorly.

While that wouldn't be my first choice, it would be nice to have an option to set your base line up or down, ie you were a law-abiding citizen your whole life or you are well known to the local constabulary where you grew up....

I'd love for that to happen but every time it comes up in game mechanics its always the same old thing. How do you set up an alignment points system and how do you enforce it. How do you let players recover from negative alignment and how do you prevent them from exploiting the dividing line.

Nobody has found a viable solution for long term games like mmo's

Isn't that basically a crime system which they have yet to implement into the game?

UO and Lineage have a pretty good one. EvE has basically the same as those with some tweaks. They work really good.

With no crime system being in by launch I don't see you being truly evil in the game. But, we do know that you are given choices on how to complete quests. So I can easily see it where there will be options to complete quests in a more "evil" manner. But don't expect to be able to run around and just kill any NPC you see, or pickpocket anyone you want since there is no crime system.