I have just created a package that allows for per language/syntax settings which can be saved within the main config.cson. It works off the file extension at this point. An example can be found at the package page.
I Just updated the package so that it now uses the grammar scopeName to specify what language the settings are for. Makes the package a lot better.
Update (11 Mar 2014):
The package is now far more stable. The structure for the settings is far better and the code has been refactored.