This is a matter of some controversy. There's pressure to shift away from using it in gender-neutral contexts, but there's certainly no broad agreement.
Folks is a classist, and refers to commoners, which might be considered offensive to those in the audience with aspirations, as well as to those in the audience in the upper class.
Note, that was slightly tongue in cheek, but this is apparently what we do with words today... find some way in which they could be considered offensive, and then immediately begin to take offense at them.
While I understand that there are indeed legitimate reasons to encourage people to choose their words thoughtfully, I can't help but wonder how terrible life will be when choosing to take offense at the innocuous becomes more prevalent than simply choosing not to take offense. The latter is, I believe, the more enlightened path.
If you want to play it safe, use "folks."