One of the actions I took back from the CDT summit was to explore how to use the Language Settings Provider with it. I think we agree that we do need the same functionality that it provides for all types of projects.
My initial investigation, though, shows that the provider system is intrinsically tied to the project descriptor system, and ICConfigurationDescription in particular. Almost all APIs reference it.
The new system is based on the platform resource's IBuildConfiguration. It appears to me that I will probably have to duplicate the entire language settings provider system to work in that new architecture. I'm OK with that. I just wanted to give people a heads up and see if anyone can think of a better approach.
The only one I can think of is to bridge ICConfigurationDescriptor to IBuildConfigurations, but that wouldn't work for the new style projects as I want to avoid the old project descriptor system.