Outside of those US states and Canada, all except one of the nations that have legalized same-sex marriage are in Europe or, interestingly enough, South America. On the other hand, the fight for same-sex marriage has been more difficult in the Asia-Pacific region, where only New Zealanders have that right. In Thailand, where more gender-reassignment surgeries are performed than in any other nation, same-sex civil unions, let alone marriages, still aren't legal. In fact, gay Thai people aren't even allowed to donate blood!
In this region, it seems, it's a victory simply for trans people to be recognized in their "new" gender, even after having had surgery. Now, for the first time, Hong Kong is allowing a trans woman who underwent surgery five years ago to marry her boyfriend. Although the British returned control of Hong Kong to the Chinese in 1997, the island still maintains a separate legal system from that of mainland China, where transgender people have been allowed to marry in their "new" gender--but only to members of the "opposite" sex--since 2003.
In Australia, there is pressure to legalize same-sex marriage. I think it will happen soon: After all, New Zealand did it. Also, while there are vocal conservatives and religious people--and, as some gay Australians have told me, more than enough homophobia to go around--religion probably plays less of a role in politics than it does here in the US.
If and when Australia legalizes gay marriage, will that be a "tipping point" for the rest of the region, as some have suggested? Will Hong Kong, China, Thailand and the other countries of that region allow people to be married as the people they are to the people they love?