Our friends at The Digital Bits have confirmed with "studio and industry sources" that 20th Century Fox Home Entertainment will release the '
Alien' anthology on Blu-ray during 2010, so it seems that the studio would not wait for Ridley Scott's future reboot/prequel. Reportedly, this set will include all four films in the series, all of the bonus content from the 'Alien Quadrilogy' DVD box set bonus content and substantial new, BD-exclusive material as well.
As usual, the above is unofficial until there is an announcement from the studio.