I don't consider wanting to be able to marry wanting to become heterosexual. I'll be honest, I know of gays that want the term "civil union" used over "marriage". However, I have seen issues historically and within language of having the two as truly the same and equal.
I look at it as removing an artificial gender restriction on the exact same commitment. Since it is the same commitment, it should be known by the same title.
Feminism had substantial forays into the theory of androgyny (think Virginia Woolf), of having what is actually a genderless society. Also, as women were often objectified based on physical attributes (stating from the feminist point of view), they attempted to break away from having the attributes to objectify. Not to mention the considerable overlap with lesbians...
