A written style for oral communicators?

This paper cites instances which point to the conclusion that speakers of non-literary languages have an innate feel for the need of different styles to be used for oral versus written modes. One implication of this is the necessity of starting literacy programs early in the life of a translation project, so that emerging mother tongue writers and editors have time to develop an acceptable written style, which can then be reflected in the translation. However it is also true that the majority of speakers of minority languages in the Third World are basically oral communicators, and in many cases are indifferent to or even resistant to literacy. But the answer does not seem to lie in considering oral versus written styles, but asking how we can best combine oral and written modes to communicate most effectively to our audience(s).