Since the 4 disc release versions of these films have the commentary, I don't see a boxed set of the trilogy offering the "definative" version of these films.
I think that it is good that the theatrical released versions of the films are available (although I wish that the longer versions of the films had been released the first time). It sounds like that when the Star Wars films eventually come to DVD, they will be the re-edited versions, not the original theatrical released versions (which I have on laserdisc).
I passed on getting the Criterion laserdisc of Blade Runner. I want to keep a copy of the theatrical version (without the added footage from Legend and with the original voiceover narration from Harrison Ford) but I don't have one. To me, this film needs to be seen on a big screen (as does Lawrence of Arabia and a number of other films). There are some films that I don't want to own home versions of because they pale in comparison to seeing the films on a big screen.
I saw Peter Sellers/Blake Edwards' The Party on a big screen and got the DVD. Funny film but since the house itself is a "character" in the film, the size of seeing that house on a big screen just works so much better (as do several sight gags). I didn't realize how much that big screen played in making the film even funnier.
I finally saw It's A Mad Mad Mad Mad World and I like it better on a big screen but I think that it works fine on video.
I saw the WB archive print of King Kong (one of the Turner properties). That print looked better than any I had seen on video or a big screen before. A good print will always look better on a big screen but sometimes a film really only works on a big screen (to get all the details or sense of scope). I can watch King Kong on video.
I realize that I seem to have wandered from talking about the availability (or lack thereof) theatrical versions of films to films that only work on a big screen. My link is that Blade Runner. I prefer the theatrical edit but I may never see it again on video and don't stand much chance of seeing it on a big screen either. Even if it were on video, I don't think I would buy it (unless it became impossibly scarce).
The Lord Of The Rings films do have some editorial changes (a line of dialogue here or there) in addition to the extra footage. I don't see much being lost in not offering the theatrical edits of LOTR. A "better" DVD technology would employ seamless branching and offer the viewer the option between watching the theatrical or director extended edit.