Gendered first-person pronouns in Japanese?

[pauamma]

In a recent IRC discussion, someone mentioned that Japanese first-person pronouns could be gendered in some contexts. That got my attention, because I remembered this as an uncommon language feature, and I found that according to WALS, Japanese doesn't have it. So I'm wondering whether WALS is wrong on that point, whether I'm looking at the wrong feature or misunderstanding what WALS says, or whether WALS and the people who mentioned this were speaking of different things, eg grammar vs. gender-related social rules about language taboos, or different registers or contexts like normal speech vs. song.

The pronouns mentioned and their genderness connotations, as described by one of the discussion participants, were:
- ore: almost entirely male - there are apparently some girls that use it, but that's weird and deviant, so...
- boku: slightly less male, but still. Male, generally (also pretty young!)
- washi: solely the province of old men!
- watashi: either
- atashi: feminine
- waga: fairly archaic, so I was told not to gender it, when it came up in my honours thesis, but if nothing else it's heavily status-based (from what I've seen it used
in pop culture, anyway), which tends to nudge it to the male end of the spectrum anyway. I've only seen it used by a woman once.)

Anyone (native Japanese speaker and or familiar with language genderedness in Japanese) can clear this up?