I think the only time people get bothered by someone playing as the opposite gender (and, in particular, men playing female characters) is when it's being used to prey on others in some way. Playing a female to pretend to be one to get free stuff from others, get closer to IRL women for nefarious purposes, that kind of thing. But some of these things occur even without the character-gender factor. And ultimately, I am of the opinion that in an MMO it is no one's business what gender you are on the other side of the screen. If a situation arose where it mattered--sure be honest. I just can't think of too many scenarios where that would be the case? But that's just my opinion. I think too many men get maligned for playing a female character when there's really no negative reason behind the choice.