Basic sourcemaps support

I think that HTTP header mapping is a better solutions in a lot of cases: as @DavidSouther says you can concatenate different stylesheets, you can minify a stylesheet (and keep the source mapping), you can serve the source map for some environment (dev) and not for production without having to modify the file (which is necessary for some systems that use the file checksum as an identifier), and of course any combination of those.

So yes, removing the embedded comment is a possibility, but an option would be much better.