For me the issue is standardization. Once all of the manufacturers settle on a standard for axles, spacing, and all of that other crap, then I'll think about it. Just because the UCI says they want something, doesn't mean the manufacturers are going to jump on board immediately. This is going to take years to sort out to the mid and lower tier bikes.
I've tried road cable discs (BB5/BB7) and cable-actuated hydro. They were alright, but nothing that made me jump up and down and immediately convert. I haven't had the opportunity to try full hydro on a road, so I'll reserve judgement. I ride a lot in the rain, and I do a fair amount of descending. I'm at least interested in the concept.
Another factor for me is the money I have tied up in 10 speed components. I like what I have and see no reason to change until it's unsupportable at the current level of components. That hasn't happened, and nothing I've seen or tried with 11 speed (including Di2 and hydro) has made me want to jump ship. Maybe later, but I'll let other people be the early adopters.