Are "literally" and "metaphorically" synonymous? [duplicate]

My Webster's defines hyperbole as

exaggerated statements or claims not meant to be taken literally.

So it would seem that using literally as a hyperbolic expression would be to negate its sense of non-literalness.

Dictionary.com has the following usage note:

Since the early 20th century, literally has been widely used as an intensifier meaning “in effect, virtually,” a sense that contradicts the earlier meaning “actually, without exaggeration”: The senator was literally buried alive in the Iowa primaries. The parties were literally trading horses in an effort to reach a compromise. The use is often criticized; nevertheless, it appears in all but the most carefully edited writing. Although this use of literally irritates some, it probably neither distorts nor enhances the intended meaning of the sentences in which it occurs. The same might often be said of the use of literally in its earlier sense “actually”: The garrison was literally wiped out: no one survived.

Despite this, I'm going to continue criticizing this use of the word. It's become trite, overused for emphasis, and waters down the word.