You might want to approach Paleo the same way as you would a religion. MikeD's point about how we're true believers leads me to observe that Paleo converts aren't much different in behavior from born-again Christians. We often incorrectly believe that given enough facts, figures, and scientific studies, that any person should follow the logic and convert to the Paleo Diet. But obviously it doesn't happen. Instead, what's actually happening is that you're attempting to change your wife's belief system: her beliefs about what is good and evil, in her food choices.
So put yourself in your wife's shoes: if your wife were trying to convert you to another religion and she talked about it constantly, and kept proclaiming how much better your life would be if you'd only convert, well, it's easy to imagine how irritated and resistant you'd be as well. Moreover, the implied sentiment behind the statement "Your life would be so much better" is that she is inferior to you for not choosing Paleo and more importantly, that you don't respect her decisions. And that will make her defensive and resistant.
What's the answer? It seems like the relationship is a little strained as a consequence. You need to take a good hard look at the way you feel about your wife in terms of her eating habits. Yes, you have great health, but your wife needs to know that you respect her beliefs and her decisions. More importantly, show her that you respect her decision to not go Paleo, even if you don't agree with the decision itself.
So take Paleo off the table. Stop talking about it with your friends, with her. And stop with the food divorce; you both are isolating yourselves during what is a quintessential human experience: the preparing and eating of food with loved ones. This isolation basically reinforces the sentiment "You're on your own; do what you want." That's not a good sentiment in any aspect of a marriage, which should be about teamwork. So show in your actions that you support her decision by helping her prepare her half of the meal ("Want me to boil up some pasta for you?), and ask for her help in preparing yours ("Can you help me out by chopping up some asparagus?"). Then when you eat, offer her bites off your plate and have bites off her plate, YES, even the pasta! If you're taking one for the team to show her you care, it's not a hard sacrifice to make.
I hope that helps. My husband was the first to convert to Paleo and it wasn't until he took Paleo off the table, that I became interested and willing to learn.