Jeff, I hope you're right---on both counts!
The reason I think leaglization won't happen soon is because Democrats will come under heavy fire from the right. I also think there will be more resistance from within the Democratic party that one might anticipate. Again, the demonization of marijuana is very deeply rooted in our culture, and I think many politicians will weigh the potential damage to their career, then opt for the safety net of that comes with taking a "not on my watch" stance.
I'm a child of the 60's-70's, and believe me, we thought there was no question marijuana would be legalized once we were adults, and people our age dominated politics. Wrong!
I believe this to be the dominant reason for our miscalculation: Many former pot smokers have stopped using by the time their children are teenagers, and they are not jazzed at the notion of their kids experimenting with it. Consequently, their former pro-legalization stance goes out the window. And frustrating as it is, many people simply tend to become more socially conservative as they progress into middle age.
The right will use every scare tactic in the book to demonize liberal politicians who support legalization. And when Republicans come back to power...well, we all know that usually catapults us back into the dark ages any number of issues. I mean, who thought there could possibly be a serious demonization of science in the 21st century? But it happened.