Ah, somehow I'd forgotten completely about the changes done for the blu-ray release in 2011.

Still, I wouldn't be surprised if LFL decides to do an ultra-thorough, frame-by-frame 3D conversion from fresh 4K scans. Look at what happened with Titanic. From what I've heard, that conversion was so thorough that it looked as if it could've been shot in 3D. Granted, Cameron's only ever used spherical lenses to shoot his movies, so that's one huge advantage the anamorphic OT doesn't have (Clones and Sith will benefit immensely from their spherical origins, whereas TPM was shot with anamorphic lenses just like the OT). But if Lucas really wants to wow us, he'll do a Titanic-level conversion and blow people away with a 3D trailer for Star Wars "like you've never seen it before."