I think we developed a lot more respect for each other. I went back to work at 6 weeks after each child and my husband works evenings, so he had 6 week old infants alone full-time before working full evening shifts. He had no previous infant experience whatsoever. :) We had a bit of family drama, which was an issue before child birth, and the four weeks we waited after delivery to have sex again was a long four weeks (of course we did other things, but it was still a long wait).
I think the other change that has been a little annoying, but only if we think about it, is that we have to wait until the kids are asleep before watching a lot of movies we like. That is not so much a problem as it is an adjustment. Because we share child care and work we don't really end up thinking one of us is more tired or works harder. I do more housework, which I hate, but other than picking up the floors, he doesn't really care about it, and I do. (He also has asthma and I kind of like him breathing.)
I guess the "cures" for any issues we've had has been to once in a while get out together (at least three times a year is what we manage), to get some time alone (even if it is just a run to the grocery store or mall), and hanging out in the evening for a bit after the kids go to bed.