It isn't a misuse. The word 'literally' has been used as an intensifier
since the late 17th century. The
dictionary also supports its use as an intensifier.
If the word has been used that way for over 300 years and has a supporting entry in the dictionary, I think it's fair to say it's a valid use of the word.
I'm replying because it's a pet peeve of mine when people claim the word literally is being used incorrectly, when it literally is not. Unless it's Archer.
This is the link you used:
literally (adv.) 
1530s, "in a literal sense," from
literal +
-ly (2).
Erroneously used in reference to metaphors, hyperbole, etc., even by writers like Dryden and Pope, to indicate "what follows must be taken in the strongest admissible sense" (1680s),
which is opposite to the word's real meaning and a long step down the path to the modern misuse of it. "We have come to such a pass with this emphasizer that where the truth would require us to insert with a strong expression 'not literally, of course, but in a manner of speaking', we do not hesitate to insert the very word we ought to be at pains to repudiate; ... such false coin makes honest traffic in words impossible." [Fowler, 1924]
So, your link says using "literally" in reference to hyperbole is erroneous misuse. Fowler's quote is perfect. If this word we have to signify "actually, without exaggeration" is degraded to mean the opposite, then how does one easily communicate "actually, without exaggeration," Sir? Besides, even if literary figures like Dryden or Pope would misuse "literally" once upon a time for poetic effect (they were poets, after all), that isn't the same as the widespread misuse in common parlance that is fairly recent and not in the context of poetry.
