It will take years for the federal courts to figure out how to recognize gay marriages from other countries and from U.S. states that allow them. In the meantime, it's all going to be up for grabs.
Canada does have gay marriage, but in most other countries it's some variation of civil unions.
I live in France and that's what they do here - although breeder couples are also allowed to choose civil unions instead of marriage, so it's somewhat more equal.
For me, I'd be fine if the federal government gave us all the legal protections of marriage - even if that means calling them civil unions.
Call me crazy, but I've always found the "marriage" idea pretty gross - though I'd love the tax advantages and the ability to make medical decisions if I had a lifetime or long term partner.
"Marriage" to me brings up images of white picket fences, bad sex and social pressure to be monagamous (not that infidelity isn't rampant in straight marriages.)