do not have to recognize marriages from other states, it will get the ball rolling and any state that does not legalize gay marriage is going to be losing a huge amount of money from people going to other states to get married.

all of those states recognize their marriage. Any thoughts on this?

I think the case is going to come down to the Equal Protection Clause, including the established judicial concept that states must recognize the laws of other states, including marriages already recognized.

I searched it and read it but I'm puzzled. Would that also include my same-sex (legal) marriage from Ottawa, Ontario?

Unfortunately, unlikely. US doesn't recognize the laws of other jursdictions, unless there is some connection to a US citizen, and even then, US courts typically have US laws trump others.