My guess is that we're getting total radio silence from Disney because they don't want to announce anything at all until the time is right. They want it to be a grand announcement, press release style.

There are so many variables to consider, it makes my head spin:

-The 3D conversions. Could this be a big reason for the 4k restoration? Also, wasn't there a demo shown of AotC in 3D at a convention in Germany? I've said it before and I'll say it again, RotS is already pretty three-dimensional just in regular 2D. I wouldn't be surprised if they put out those last two prequels in 3D, even if it's a short run to get them out of the way for the OT. I'd be equally unsurprised if they simply skipped the remaining prequels. Or maybe they've completely lost interest in the 3D versions, who knows? A theatrical re-release kinda seems like a no-brainer, though, especially with Episode VII around the corner.

-What to include or not include in a home video release. The films are yet to be released individually on blu-ray. This presents an opportunity for the blu-ray equivalent of the '06 dvd, only without the bullshit this time. The question is, do they go the simple route and include only the most recent version and the original version or do they include the '97 version as well? Or do they keep it even simpler than that and just release a 3-disc OOT set?

-The situation with Fox. Does Disney release it through them or do they pay Fox to license it out? Fox is making money either way. Could this prevent Disney from giving a hoot about the existing movies? We've heard rumors that they're only focused on the new stuff. The existing blu-rays from Fox aren't going anywhere. Still, I would think they'd want to make a finished, polished, mastered-in-4k version of the movies before the new movies come out.

.... And about a million other variables that Disney is no doubt considering right now.