That is the WRONG ANSWER. If they really love their country, they will stay, and work hard for the next few years and take another swing at it. No one said gaining equality was easy or quick, and it shouldn't be because things that are easy or free have no value. It was 145 yrs almost exactly between the final emancipation proclaimation and last night where for the first time at the highest office in the nation there was true equality even being considered. (how many times has jesse jackson run for president and gotten like not even 1%?) 70yrs ago racial segregation was alive and well. 50 yrs ago it was illegal for interracial couples to marry. Today we look back on those things with chagrin at how backwards society was.
I have a lot of faith that in our lifetime we will see gays as truly equal in this country. But if people just give up at the first or second or fifth setback, they don't deserve the equality they claim they desire.
I have no respect for people who say "i will leave the country if ___". That is not how democracy works. You win some, you lose some, and when you lose you turn around and fight harder so the thing you were fighting for has meaning, and you show that you honestly believe in what you are fighting for. Social Change comes slow, but I believe every setback should be taken as a challenge to truly make a change. Lets get to work on an amendment repealing the amendment to place on the ballot in 2yrs.
EDIT: this post is specifically talking about Californians moving to Canada not the rest of the country. Do what you want, you people always do anyway, and I really don't care about national politics ironically :D