I've seen a lot of threads on these boards bashing the idea of doing a honeymoon registry. There's a common concept that a wedding gift should be something timeless that the couple will have for the rest of their lives, and will make them think of the wedding and their guests for years to come. I agree with this ideal. However, a considerable amount of psychological research shows us that experiences (and the anticipation before and memories following these experiences) bring us more happiness than material things. Therefore, I think it follows logically that a honeymoon registry would have more long-term impact for the couple than a traditional registry for household items.
For anyone who's interested in more details, this is worth a read: http://www.theatlantic.com/business/archive/2014/10/buy-experiences/381132/
I'm not trying to start any arguments - everyone's preferences are different. I just think it's interesting food for thought.