I definitely think that love is extremely important, even essential in a marriage. But love doesn't need to be full-out passion. With time, I've changed my views about these things. I used to think love with all the passion like what we see in the movies was so ideal and beautiful. But I've learned that what is really beautiful is not a passionate love, but a love of respect and caring.
It makes me think that ideally, marriages *should* be "arranged". Not fully, in that the person envolved has other people make the decisions, but arranged that the people looking for partners get to know each in a more "on paper" kind of way. Things they believe in, things they want in life, things they like to do. And of course through this "dating" type period, they will be able to tell if they like this person and even love, but at least it won't have been based on that blinding passion. It literally blinds you so that you don't see how ill-matched you are. It blinds you to all the problems you are likely to have down the road.
I've become "cold" with time. Not even over a period of 20-30 years... I'm only 22. But I really, really, really think that the one thing people should make sure they have with a partner is RESPECT! And the second is to have things in common. Great if you have passion on top of that, but best make that passion grow with time. Don't get caught up in it before you're sure about all that other stuff (the important stuff)!