Over at the AVS Forum the specifications for the Blu-ray release of the Alien/Aliens etc boxed set have been posted. Looks like they’ve got a healthy ~26Mbps MPEG4 AVC transfer.
Two points of interest: although a Fox title, they are region free. Looks like all the major studios are abandoning that silliness, although region coding will no doubt live on through the smaller distributors, who are typically required by contract to apply them.
Second, in addition to 5.1 lossless, the first two movies have a 4.1 track Dolby Digital track (at 640kbps) for their theatrical versions (both director’s cut and theatrical versions are provided by means of seamless branching). This is apparently the original sound, although that would have been presented in cinemas as ‘Dolby Stereo’ (as the cinematic version of Dolby Pro Logic was called). My guess is that that the 4.1 is actually 3/1.1. Rather than encoding the four streams down to two using a matrix process, apparently they’ve simply allowed them to have their own discrete channels.
Except that back in 1979, there wasn’t a 0.1.