1080p is actually a better resolution than most think. Lots of misconceptions regarding the resolution of film.. A 4K+ scan of SW would've been wise though, but it's doubtful a film from the time period has 4K of info.. Likely 3K tops and much less at a normal 'viewing' MTF response of like 50%.
Every now and then somebody finds release print of varying quality (dye transfer, 70mm, 35mm) and there always are a bunch of requests to scan it and release it on the internet so we can watch in on our PCs, Blu-Ray, etc. The results would probably make a disappointing Blu-Ray though, dirt and fading aside. Release prints lose contrast and resolution fast from constant projection, and Star Wars was a blockbuster so any surviving print would definitely have been projected quite a bit. 35mm release prints have around 1000 lines of horizontal resolution due to generation loss in the duplication chain and less when projected. Vertical resolution is even worse because of how the two films (during duplication) make contact traveling at slightly different speeds. 70mm isn't a good idea at all because SW was shot on 35mm. It would've had to be blown up optically to 70mm which causes degradation (70mm was used mainly for the 6-track audio). People like dye transfer prints because the color doesn't fade, but they also have a lower resolution because of the process used to make them.
4K as a scanning resolution and 4K as a display resolution are two different things. That's not to say there is no excuse to not have scanned SW at 4K to capture as much detail as possible, but from there it could be downsampled to 2K with that detail which wouldn't have been in a 2K-only scan. 2K is basically 1080P (1080P is an HDTV format referring to vertical res while 2K refers to horizontal. 1920 compared to 2048 is not much different). The reason that Wizard of Oz and Gone with the Wind were scanned at 8K was kind of like a "well why not" thing. Most hollywood productions are digital intermediates (and avoid most of that generation loss in duplication from neg>IP>IN>RP) and shockingly many still at 2K, especially effects scenes.
4K as a display resolution in the living room doesn't make sense right now. At a normal viewing distance on 50" TV you still can't get the full benefit of 1080P. 4K would be diminishing returns unless you're projecting it on a large screen. (But I'm sure they'll have something like 'retina display' OLE wallpaper someday replacing TVs and projectors anyway)
Sorry to get off topic, I've been reading here a long time. Blu-Ray is still a compressed format with 4:2:0 chroma subsampling and the occasional artifact. Most properly authored discs look great though, best consumer format there is.
I guess I will buy these but I wish they were available separately so I didn't get the prequels. Hopefully no sound/color problems this time. Maybe if we're lucky they'll include HD scans from the oneg for the scenes they took out so somebody can make a proper HD fan edit here. Doubtful though. Just because they can scan films at 8K and even though it's overkill, I do wish Lucas would do it anyways. If WB is doing it in bulk with all their catalog titles, Lucas excuse of it costing too much is BS. But 1080p will make a nice Blu-Ray :)
some sources (in case anybody cares):
http://www.etconsult.com/papers/Technical%20Issues%20in%20Cinema%20Resolution.pdf
http://www.cst.fr/IMG/pdf/35mm_resolution_english.pdf
http://www.arri.de/camera/tutorials/4k_systems_theory_basics_for_motion_picture_imaging.html
http://www.hometheaterforum.com/forum/thread/227113/technicolor-films-on-dvd
http://whatsonhdtv.blogspot.com/2005/07/2k-4k-who-do-we-appreciate.html
http://digitalcontentproducer.com/mag/video_digital_cinemas_special/
http://magazine.creativecow.net/article/the-truth-about-2k-4k-the-future-of-pixels