Hmm, my suggestion wasn't to treat everyone the same, that doesn't seem reasonable or like a good way to achieve our goals.
Rather, it was to blur the way identities are formed - from having male or female names with male and female personalities and roles to focusing on the content of our work and forming communication and identity around this - maybe this could start with a simple change to how names are handled - instead of using your real name, you have to pick a username. It would seem wrong to intentionally prevent someone from picking a manly or girly name - but I would hope this would at least offer some women the chance to pick neutral names and not give away their identities without having to assume a male identity as you're mentioning.
As a software engineer, I see the women trying to become "one of the boys" as you mention pretty often, they either do this or assume a less technical role (as if only men can have technical positions). But if you remove the ability to tell whether your collaborators are male or female, and create a culture of focusing on generating personal identities or social status based on qualities other than birth-name, gender, race, etc., such as what project you work on, your strengths, or what you find rewarding in life, you might find someday your collaborators are a mix of women and men without ever realizing it - the stereotype of the white male contributor thinned out without anyone knowing.
Creating a sort of anonymity isn't going to be easy- people will want to identify themselves as male or female naturally, as it's a part of how we distinguish ourselves in the outside world. This could ruin a plan like this - but I like the idea nonetheless on the principle of it. It provides opportunity where currently we have stereotypes, and it might still have some positive consequences, even if not radical.
I think the culture in general (not just with Debian) will have to change from one in which only white men fulfil technical roles (where QA is apparently the only exception) to one in which gender and race play little to no role. However, we can take more of a stance without outright "we need women" - which seems artificial and not true to the heart of the problem. Reducing personal identity in the leadership might help too - if there is no face with a name, and a name is nothing but a designator that reflects a personality more than a body, it's easier to look at a project and not immediately think "I'm alone here - everyone else is a white male". Think - even now you can research who is serving whatever leadership role on wikipedia - once they're high enough up. You generally find the project is lead by some white guy, which isn't surprising. But what if you couldn't do this, because the name of the leader was something like "Cloud" or something...
Eh, this wouldn't work - people cling too closely to the way things have always worked and would name themselves according to their social structure separate from the project (either with a name which designates gender in some way, or with things that men traditionally associate themselves with - gamertags are a good example, if you play games, you can still tell a male's handle from a female's...)
Hopefully all of this rambling has inspired thoughts that might be actually useful?
Anyone?