There is a bill before parliament right now (bill C-389) that wants to make it a criminal act to discriminate against anyone on the grounds of gender identity or gender expression. If you translate this into real life, having separate washrooms for men and women could be construed as discrimination.
The way I see it, a man is a man and a woman is a woman. The plumbing says it all. We don’t need gender identity imbedded into the Charter of Rights.
Personally I’m not ready to share a washroom with a bunch of men standing at urinals. And I’m sure they don’t want to share that space with me.