It depends on whether you're talking about an actual whole new, radically different language or something that is essentially C "with improvements". My point is not that C "with improvements" is the ideal approach, only that (at this time, for almost purely social reasons) I don't think C is really subject to replacement except by something that allows you to mix standard C and the "new language" because, apart from specific improvements, they are the same language.
This might come with huge drawbacks, but it still seems like the only socially acceptable way to fully replace C at this time; make it so you can replace it one line of code at a time in existing projects.
This might come with huge drawbacks, but it still seems like the only socially acceptable way to fully replace C at this time; make it so you can replace it one line of code at a time in existing projects.