Right or wrong, I've asked many female friends if they mind the term "guys" as a general reference to a group of people, and none of them mind it. Your milage may vary, but I think it's considered a general term.
It's a general term in social groups when I am not worried that someone actually forgot there were any women in the group of us going out that night. It's a trickier term that seems in my experience to correlate well with "there are no women here" or "I forgot there are any women here" when used at work, and so it is a slight negative indicator in professional language.