My own feeling is that this could be the best thing, because Disney has always been kind to its classics, has always marketed itself based on its legacy, and with Lucas out of the way--he's a creative consultant on the sequels, not on the companies business dealings--there's really nothing holding them back.
But Lucas will become Disney's second largest individual shareholder, after the family of Steve Jobs. (One thing nobody I've read seems to have pointed out is that this deal in some way reunites Lucasfilm with its' former computer graphics department, which ended up selling to Disney several years earlier for much more than Lucasfilm itself.)
Lucas' having such a large stake still carries a whole lot of weight, even if it isn't an outright veto (it's still just a small percentage of the company). Now, maybe there are elements within Lucasfilm who have wanted to get the OoT out that Lucas has thusfar vetoed, who will now have some breathing room. I doubt that these people could have gotten promoted in the organization if they felt that way openly though, considering Lucas' attitude though...so we'd have to hope that many there are people in the shadows who want this, or that the suits are willing to override Lucas' wishes. Otherwise...I dunno, I just don't see much of a reason to be hopeful.
The 2011 Blu-ray collection, btw, is billed as 'The Complete Saga'. I sincerely doubt that these talks have been in the works for more than a year, or that Lucas had any kind of story treatment for the third trilogy until very recently (you would have mentioned it in your book!)