So, Walter Hill's original cut will never be released, right?

That's a fkin shame. I am not huge fan of this movie but i don't think it is bad as its reputation. It definitely has some problems but other than lousy score and bad editing i don't have much problems with it. This is why i, and i'm sure some other people hoped that Shout Factory will include Hill's original cut/workprint as a bonus or at least put more deleted scenes but they pretty much failed with their edition of the movie. Not even the special features go into much details about incredibly troubled production of the movie, sht i can find more information about it online than in any of the interviews that Blu-Ray has.

For example, this old review (from July 2000) from someone who actually saw Hill's original cut mentions that other than Facinell's role, that version was lot better than what studio hacked up and released;

http://www.filmthreat.com/reviews/3312/

"A couple of months ago I was able to view director Walter Hill’s buried director’s cut of “Supernova,” and was I shocked to find that not only was his version vastly different, but surprisingly decent as well. With crucial scenes and a strikingly different temp score restored, not to mention without some misguided overdubbing and scene rearranging, performances that seemed so wrong in the hacked-to-bits theatrical cut were dead-on (though Peter Facinelli’s work as the villain remained a lost cause); barely realized pretensions blossomed into genuinely provocative themes; and there was actually some real suspense to this tale of a madman going on a rampage aboard a rescue vessel in the far reaches of space.

Alas, this far superior version of the film is not on MGM’s DVD, but a special R-rated edition of the abysmal PG-13 release version (the major restoration? Some extra nudity) credited to the pseudonymous “Thomas Lee.” However, the disc gives viewers a hefty taste of what could have been (or, rather, what was ) by including a number of the excised footage in a “deleted scenes” section presented separately from the film; in a strangely generous move, MGM also polished the visual effects work on these scenes. While these scenes’ true effectiveness don’t really come through out of context, at least audiences can get an idea of Hill’s original vision."