Sources inside both Sony and Microsoft have stated that both console manufacturers at one point considered the possibility of eliminating optical drives from next-generation devices in order to only allow content to be obtained via digital distribution solutions.
This would have allowed the two companies to have tighter control over their own platforms and would have eliminated the used game market that so many companies have been complaining about lately.
The sources say that Sony decided to drop the idea because of the problems that some areas of the world have with high speed Internet and because the game size is set to once again grow in coming years.
It seems that Microsoft used the same logic for the successor of the Xbox 360.
Presumably, the two console developers also learned a lesson from the launch of the PlayStation Vita handheld, which lacks any kind of optical drive.
Announcements about the Xbox 720 and the PlayStation 4 are expected before the end of 2012.