It's not a misuse; evidently it's a new use.
The Oxford English Dictonary, since September of 2011 has included this definition of literally:
"Used for emphasis or to express strong feeling while not being literally true: I have received literally thousands of letters.'"
That doesn't prove it's a correct use. It proves that even The Oxford English Dictionary
is not always right.
Lets rise up in protest at dictionaries giving in to yet another colloquialism. If literally now means well figuratively, does it also mean the old version of literally? Or is there a new word for that?
And while we're at it lets reinstate Pluto.