So my GSoC proposal wasn't accepted this year. Probably it was my mistake by applying it too late, but this mail is not about this.
Since a big research was already done, it would be fine to implement this feature anyway. The problem is that I still don't know what such people as Alexandre Julliard think about it. I got some positive feedback from normal users and even some Wine developers. However they don't make decisions about the Wine future and I don't want to spend my time if this feature will never get into upstream.
As far as I know there already were some attempts to do something in this direction. But interesting patches I found in wine-patches were left without any response and Wine still looks like a monster from 90s. At the same time I see a lot of patches affecting the DirectX API. Is it the official position of the Wine maintainers to keep Wine as an OpenGL wrapper? Of course there are a lot of users who just want to play their Windows games on the Unix-like systems, but the need of working with normal desktop applications is still very high.
There also were some questions about integrating new themes to the existing system. If it matters, I found a way to make it transparently for the end users. A new "GTK+" or even "Mac" theme can live together with old MSSTYLES themes without need of switching any "theme drivers" as it was said in my GSoC proposal.
Regards, Ivan