It was stated in the original StarWars.com article that it was like this:
Disc 1: 2004 Edition of movie
Disc 2 (BONUS DISC): "Theatrical" Edition of movie
The "extras" ARE the Theatrical Edition of the film. You'll have to buy all three packs to get the entire "trilogy" as there is no "boxed set" of the Original Original Trilogy. The Prequel Trilogy box set is just wishful thinking right now.
The article said these were from "masters" from circa 1993, which fans have considered to be either the "THX Enhanced" series that was released for LaserDisc or else the "cleaned up" masters that were used to create the Special Editions of 1997 (before the CG elements and extra scenes were added and tinkered with).
Since neither the THX Enhanced edition or the pre-Special Edition (or the Special Edition) masters contained the pre-ANH crawl, it's been speculated that it will be a "reconstructed" crawl (much like the fan made dvd's that include a crawl created by a fan on a computer), but who knows, maybe they'll actually clean up the crawl that was shown in the Empire of Dreams special and use that?
The 1997 editions have never appeared officially and DVD and seemingly never will.
So the "Special Edition" we're getting with the 2006 set is just the 2004 editions once again (the third time they've been released now).
The idea that "no enhancements" are being made to the "theatrical" (1993) editions is hinted in the fact that they'll only be Dolby 2.0 (but that's fine, most fans agree, since in 1977-1983 they didn't use Dolby 5.0, but then there was a 6 channel stereo version of ROTJ shown in theaters, iirc), and it will only be "non-anamorphic widescreen" meaning if you have a widescreen TV you'll have to use the "zoom" function to blow it up to take up the whole screen area... it won't scale automatically to preserve detail. If you have a regular screen, you won't notice any difference.
A few fans have criticized this information since this is being sold as the "theatrical versions" but it seems that we're actually not getting the Star Wars classic trilogy "as it was shown in theaters" but rather "as it was released on home video in the 1990's."
Still, when it comes out you know there will be reviews and previews, so you can make your decision then.
If you haven't purchased Star Wars on DVD yet, I'd hold off until this version comes out. Get it, and then go on ebay or amazon and buy a stand alone copy of "Star Wars: Bonus Materials" DVD (that includes "Empire of Dreams" and such). <--- I have seen some copies alone, normally you have to buy the 2004 four disc set to get this. Then you'll have "everything" for the classic trilogy on DVD officially released, without having to "double dip" anything.