I'm clearly in the minority here, but I think people want to give gifts. Not everyone will, but for those who do, some direction would be appreciated (I know I would appreciate it). So we are doing a registry more because we are having a big going away party (instead of the AHR due to being married near the holidays). And also partly because I think even some who will be coming to Mexico will want to give something, even if it's small.
Since we live together, we have a honeymoon registry and a registry with mostly gift cards for our favorite restaurants and the pet store (we love our dog!) in $25 increments. I think this will be greatly appreciated by folks and if we get nothing, no big deal.