Blu-ray digital tech may have a higher definition than movie theatre screens can display now as most movies theatres still go by projection, aka a lower quality and ancient method. You can't compare that with the extreme-HD capabilities blu-ray has.
I don't think movie theatre screen quality can match blu-ray quality on say like a sony bravia LCD flatscreen or plasma tv with digital surround sound.
The only thing a movie theatre screen has over flat panels is size. And even that area is beginnig to seem unimportant now that a big tv isn't even a big deal to get anymore..
__________________ "The darkside, Sidious, is an illness no true Sith wishes to be cured of, my young apprentice .."