V's gender is simply indeterminate. It's a bit like arguing what I've had for dinner 100 days from now - I haven't decided yet!

V was originally written as one sex, generally assumed to be male as the "us" ending is traditionally male for latin words and he's referred to as "man" in a couple of the early strips. Once the debate about V's sex started up and the comments on the androgenous look began, Rich decided he liked the idea and V was retconned as of indeterminate gender. Not as male, or female, but it's hard to tell - actually indeterminate.
Until Rich Berlew himself decides what he's going to make V's gender, there's no point in debating it. I don't think he's sending secret messages and coded hints as to what it really is - what it really is is "I'll decide when - and if - it ever becomes necessary".