Well it doesn't loon good for the special features disc (disc 9) for anyone hoping that we're going to get high quality versions of the old docs. Looks like Lucas is pulling a 2006 bonus DVD on us again. I've been having some PM's with someone that knows a bit about the sources used for the discs and i was sent this reply (edited to removed clues to identity)

Ady

After your recent conversations with [deleted] i was asked to contact you because i have a little more knowledge on this subject.

I do know that there have been some minor color alterations but i cannot comment on the extent because this was not my department.

The original special feature documentaries will only be on the final disc in the complete saga collection. These, however, could only be presented in standard definition. While there are copies of 16mm prints for these documentaries, there was no green light given to use these for the source of the special features. Instructions were given to find the digital masters which were used for the original release versions. I am unsure if these were the same used for the VHS or laserdisc copies but a colleague informed me that these masters were produced in the 1980's or 1990's (although i cannot confirm this). As far as i am aware no post production work was done on these masters to prepare them for the Blu-Ray collection. Having seen [deleted] at [deleted] there seems to be some issues with digital artefacts caused by the interlaced source used and from the original digital conversion. The same procedure was used for some deleted scenes seen in the Empire of Dreams documentary as these scenes were also taken from older digital copies.

He went on to give me some more information that i cannot post here because it may reveal his identity. So it doesn't look good for all of the original trilogy stuff then :(