Very superficially. I haven't completely understood how much better it is than the standard layout, but I doubt that it can be comparable with what we have today in a browser. I mean all the libraries, no need to compile anything, writing components in a general-purpose high-level language… Even making Qt friends with Python isn't as effortless as it could have been.

And it isn't the real thing anyway: in order to be a good platform for building GUI apps all that functionality should be directly provided by the DE in the first place (like it is in Android, for example). You cannot play with representation the same way in (say) xfce, as you can in the browser console, moving containers and changing colors as you like.