How does your alignment effect gameplay in SWTOR?

[Venant]

While questing you get 3 options for dialogue choices in the game, and it seems like the options follow the classic good/neutral/evil choices for how you respond. From what I can tell, how far into either the light or dark side you are aligned is effected by these choices while leveling. Is it possible to have say a light side aligned Sith Warrior if you always pick the 'good' option, or a dark side aligned Jedi? (This doesn't make much sense since it seems each side is mutually exclusive to their side of the force)

Can anyone that has played in the beta already elaborate on what this system does aside from giving dark side users dark corruption aesthetics and effecting your lightsaber color options.

[Amnasty]

it also effects how your companions view you and other quest lines that become available
also BW has stated titles like Darth can be giving depending on your alinement but wont be easy to obtain. This makes your choices criticle which threw the woven story can be hard. What may seem like a dark sided choice may not be the darkest sided choice needed =D.

[Nyctanessa]

Force alignment also gets you access to Lightside/Darkside gear. YES you can pick darkside options if you're Jedi, and the opposite goes for Sith. There aren't always three options, sometimes only two, and the max I've seen is four.

[Jamber]

There are often three choices in dialogs. To be frank, 85% of these choices do nothing other than give flavor to your character. Another 10% of options wouldn't affect lightside/darkside level, but MAY change the direction of the dialog, either ending it or opening other routes. The last 5% of choices are morality choices. You have to think of lightside/darkside from dialogs seperate from the force, because non-force users also follow the same mechanic. That should help clear things up a little. The morality choices can either be "dark" morality choices or "light" morality choices.

You can either decide to let the cheating wife of a ranking official who lost secret plans to her lover go, or you can assassinate her. You can intimidate a rich poacher to leave the forest of pay him off.

The choices do not necessarily line up with the force light and dark. The dark side of the force does not encourage mindless slaughter and causing pain, but trusting in your feelings, growing them, and searching for power. If you think of the darkside that way, where you search for power in any way best for you, sure you're gonna step on a few feet, or heads, but you're not a sociopath. If you differentiate this way, I'm sure you can then understand the lightside/darkside morality choices within the game.

You can have a lightside sith warrior. He prizes honor as well as power. If he can have you side with him, it would be his first choice, but he's not above destroying you. The darkside Jedi uses his emotions and feels them instead of supressing them. He could save the orphanage of 10 children from burning alive, or he could first kill the guy holding his lover hostage, thinking first for his love, and the "greater good" second. This doesn't mean he's gonna go kill children (Not saying a darkside jedi CAN'T do that...but he's really "falling to the darkside of the force", an option that won't let you switch factions XD)