A true OS aimed at "creative" in my opinion needs much more than this. To name a few things:
- OS level handling of color information and an OS API/CMM which every application accesses and uses (no app-specific color management and no app-specific algorithms and "rules". Same for printer drivers
- specialized file system which offers the possibility to actually have "asset" folders. Not the possibility to create a folder and name it assets, but an actual logic to files stored in it's parent folder which different applications again can understand and access. Same goes for projects. The OS has to understand what we are working on, and not give us the possibility to think up our own project folder structure, which is different from company to company to freelancer
- integrated, transparent versioning of projects, their main files and assets. as simple right click => "create versioned directory/project", with an OS API which the applications hook into. the file manager needs to have the possibility to easily roll back the whole folder including assets to version 06, for example, without losing other version. easy ability to branch from one version to another and develop them simultanously. this needs to have a very good UI so I can QUICKLY find what I am searching for
- these functions need to work on network shares, with multiple users, and need an easy export/import feature, so I can export/pack the project, send it to an external, and get the new one back, and I can quickly and easily import it back in.
- fonts are assets! not something you hide somewhere in the OS folder. also, and I mean it: some kind of DRM fonts, so I can send out copyrighted fonts to an external which will only work inside the project folder I just exported and sent him.
- integrated time logging. set up OS wide rules which applications to log, and when to stop logging (after x minutes without mouse movement etc.). easy export of "how long did I work in project XYZ, on file XYZ, in application XYZ". Again, has to work with multiple users over the network
For most of these functions, there is a solution, sometimes even a close on in some OS (Timemachine, Shadow files) etc., but you have to piece the stuff together, and most of the times, one component or another breaks the concept due to an update, or it simply is to cumbersome for some people to handle and again the whole thing breaks down. or it is damn expensive. Many time loggers come to mind, which scan window titles to try to find out which file you are working on, and often break with new versions of applications or foreign versions.
Such an OS would be a killer app/OS, but it will never exist. If market share is low, the big apps won't be ported. And if the big apps are not available, market share stays low.
And I don't think it is possible to create such a thing as a framework layout on top of an OS...it would not feel intuitive enough, and would not hook deeply enough into the inner workings of the OS.
The only company who could pull this off is Apple, but if they would have wanted to, they would have done it already as the last three major OS versions where quite lackluster IMHO when it comes to innovation.