Not really, the other elements of sex are what keep 'regular' sex interesting; the connection, the variety of foreplay or positions, the fact that there's a real person there :D

I won't pretend to know much about the science behind it, but my understanding is that a habit of porn removes the link between being horny and then becoming sexually aroused. So instead of getting an erection because you see your sexy wife, you're getting one because you're so used to watching porn at 2 am before bed. And the extremely graphic and immediate nature of porn means that habit is a very strong one. It's like a chocolate bar in the immediate gratification and overwhelming of your senses. Whereas sex with a wife is more like a delicious but wholesome meal you sit down and enjoy. And that continues to be delicious no matter how much you eat it.

Oh, and since when was wanting your wife to dress up as Princess Leia seen as kinky? :P