Hypotheticals, transsexuals and same sex marriage

[TaraJo]

So, I thought some over this and figured it would be an interesting thought question to post here.

Back story is, my boyfriend proposed. We're planning on getting married. We don't have an exact date yet, largely because he wants to come out to his family, first.

Now, for those of you who remember me talking about the two of us, my fiance' and I are both transsexual. He's female to male and I'm male to female. That right there brings up a whole host of questions regarding same sex marriage.

To expand a little more, as far as anyone can tell, I've made the switch but he hasn't yet. So, as far as most people see right now, we're a lesbian couple. Should we, under that circumstance be able to get married?

To go into another hypothetical, let's say we met and started dating and even married before either one of us transitioned. What happens to our marriage when one of us switches? Is it automatically annulled? And if so, at what point does the government do that?

Or, if you want to handle a more practical matter for us, traditionally, when a couple marries, the wife takes the husbands last name. Some places even have laws, enshrining that tradition. What about us? Does that mean I can take his last name or that he would be forced to take mine?