I don't have the link handy right now, but IIRC there was a mention of some system level differences in how Go might like to change things in the toolchain under the language level which could move in a fundamentally different direction from the C toolchain. An example was in the area of how stacks were created and operated.

I think one could foresee making more changes in the future in that area. It's sort of exciting to think that these fairly low level foundational details which much of programming relies on, could be rethought and maybe get us to a different place than we are now.