Before robot marriages could even be considered, robots would have to be recognized as sentient beings and citizens. I'd say that it's likely that that's a bit more than 40+ years away. The advances in AI have been slow, to say the least. At this point, we're hard put to have a computer that can understand human speech. Sure, we have speech to text interpreters, but where is the natural spoken control interface? When we have computers that we can say "Oh, say, computer, I need you to burn a set of CDs of all of the project files that I've been working on that are associated with project Vilmos. Can you do that then call me on my cell phone to let me know? I'm going out to lunch now. Thanks." to and they can understand and respond appropriately, then we'll be a step closer to the idea of real AI. Until then (and likely a ways after then, even), robots that are sophisticated enough to consider marrying are in the same category as all those flying cars they told us about in the 1950s that everyone was supposed to have by 1990.