I think you misunderstand: the OED is descriptive, not prescriptive.
Of course I understand that. The OED
has always adjusted for changes in our language over time, as any dictionary should.
My point, though, is that just because the OED
acknowledges the fact that people are now using the word "literally" in that way does not mean that it is now a correct usage. In fact, the fact that OED
is descriptive, not prescriptive, makes that even more true. The editors of the OED
are simply reflecting what people do; they are not making a judgment on whether it is correct or not.
My contention is that regardless of how many people use the word "literally" as a statement of emphasis rather than a statement of fact, they are still incorrect in that usage. If a million people suddenly decided that the word "red" now meant "blue" it would not make it so.