My $.02 on this is that there are many more ras out there that people are unaware of.
I'm right on with Gary's (Aquatic Resource's) comment about Dallas World Aq. Holding area is HUGE, and not many know it's even here. While I was there, breeding was like no other set up I've ever seen. We needed specific staff just to prep food and feed pups. As for what George talked about at the Symposium, often times people in the zoo/aquarium world don't (or aren't allowed to) tell the full story. Personally, I'm not one for hiding stuff (hence the big Amazon thread I did awhile back).
I think the Elasmo Census could be an amazing tool, if used right. However, much to my sadness, people who report to it don't always have good count, correct species and by no means is it an all inclusive list. Remember not all keepers of rFW ays are ray lovers like us. Some who care for them don't even know what kind they have, anything about their hisory or how amazing they really are.
As for rewriting the books ...so to speak....we are at the edge of that right now. As we look further into DNA seperation of species, clearly defined lines will show up. I suggest until that point, we keep what we have as species "pure". Otherwise, all we will have are mutts, making it harder and harder to make sure the new reseach is valid.