Coke is definately vegan. To be honest, it's the only way I've gotten through my first week of cutting out dairy! I'm gonna play devil's advocate here, even though I definately get where everyone else is coming from. I'm having a really tough time, and being able to have something as normal as a Coke while everything else I eat is unfamiliar is really comforting! If you can find it, get Kosher or Mexican Coke-- it uses real sugar rather than high fructose corn syrup and tastes ten times better. The best Coke I ever had was in Spain-- Coke may be the American beverage, but for some reason, other countries do it better!
However, health aside, Coke is far from a "kind" company for the environment or other people (bottling plants have been known to sap local water sources in some of the poorest areas in India and other places). Just something to keep in mind! Though, I am not trying to make you feel bad about it; that would be very hypocritical. I just think the info is important. We might not be at a place to give it up now, but as veganism becomes more normal to our bodies, I think it will be easier to quit those comforts.