Star Wars: what is the 'definitive', original 1977 edition anyway?

An ad for Star Wars in 70mm at the
Granada, Santa Barbara, September 1977.
Source: fromscripttodvd.com 

Ever since the Star Wars Special Editions came out in 1997, people like me have been repeating the same tedious question: Will we ever see the original, 1977 version of the film again?