Basically, it provides LFL with several different marketing opportunities, as well as serving other interests simultaneously. I've come up with a checklist of various factors and points related to why this is happening:
1. It (mostly) quenches the demand for the OOT on DVD
2. It curbs the piracy of the OOT by making a legal product available, and thus less likely for consumers to buy copies (ebay), at least while it's in print.
3. It allows LFL/Fox to yet again resell the same SE versions during the 2006 Xmas shopping season, while using a "limited edition" sales pitch, just as was done with the 2005 SE box set.
4. By releasing these films NOW, as opposed to say next year, they are capitalizing on the tail end of the red laser DVD marketability. If they had waited until next year, when blue ray discs are more commonplace, their sales would likely be stunted, and they would encounter more criticism for releasing it onto standard DVD, instead of a blue ray DVD.
5. By releasing the OOT as bonus material, instead of as the main product, it relieves LFL of any real responsibility or motivation to put any effort into the DVDs. Their justification is that it's only bonus material, and not what Lucas intended, so digging up LD masters and transferring them is minimal in terms of effort and expense, and maximum in terms of profitability. Someone else pointed out that Lucas' ex-wife is entitled to a percentage of profit when something related to the OOT is released, so by doing it this way, it skirts the issue. I don't know if this was part of the motivation, but if this is true, then it was likely part of the decision.
6. It allows LFL to permanently wash their hands of the OOT, because they can now simply point to the upcoming release and say, "It's out if you want it".
From LFL's point of view, this is a win-win situation, because what everyone was clamoring for IS being released, albeit not in the form most expected. Personally, I am disappointed that no real effort is being made for these releases, but am also glad that they ARE finally being released in some form. Anyone can tell you that a 1993 video master -> DVD is going to look a lot better than an LD capture -> PC -> DVD would ever look, despite the fact they won't be anamorphic. Personally, I hate the way the SE versions look, with the over processed video feel to the films, the excessive grain removal and oversaturated color scheme, the audio mixing and saber coloring problems, and horribly dark picture. I'd rather watch a 10+ year old LD master anyway instead of the "restored" versions. I'm sure that once the DVDs go out of print, they will be pirated/altered in huge numbers. In an earlier post in a different thread, I predicted this would eventually happen, so it's no shock-I just wasn't expecting it so soon. I hope this can answer some of the questions as to why this is going down the way it is.