I liked Daniel's video. It provided more detail about X than I've seen from any Wayland link so far and cleared up a lot about Wayland to finally get me interested in it's development. Daniel in particular is the first person I've seen talking about Wayland that I'm interested in listening to since he actually knows facts and can communicate them well as well as have a great attitude about what he's doing
That said, and I know I'm biased in favor of X, I'm very disappointed in the solution to all the problems in X11 that he detailed. Due to issues with how X handles it's job, the solution has been for years to let the client fix it at their end and use very little of X. Avoid fixing X. The Wayland solution sounds like take that work around and build a new display around it. Not encouraging.
From his description I agree: the X11 code cannot be fixed. But, my impression is that as coders/developers they applied a coders take to the problem and came up with a coders solution: Take the code written app-side as a work around and build a design on it. Reverse engineer a design based on code that exists. That sounds really negative and I know that will raise some bile, especially since the standard answer is "if you think they are wrong, code it yourself". Based on that video, there's no way I could code at his level so there's no ground for me to stand on there.
What makes me comment on this topic is that I like the X11 design/architecture and feel strongly it is more useful now than the alternatives (RDP/VNC/etc.) and will be more useful as time goes on. I would like a designers solution in that fix the design, then work towards getting that design coded. From the sound of things, that would mean dumping backwards compatibility with X11 protocol, but I would still rather loose X to a better design than loose it to what I see in the Wayland design. Unfortunately those who would be able to handle that kind of development look to be focused elsewhere...