How much are you willing to spend for a version of PDVD that has to pay the exorbitant licensing costs for Dolby Atmos and then again for DTS X? Are you willing to pay twice as much for it? How about everyone else, are they all willing to pay twice as much for a niche feature?
How many people are going to cut holes in their ceiling to improve the sound on from their computer? Remember, most people are still at 2 channel sound! If people are unwilling to run wires to get the huge improvement from 6 channel sound, what makes you think they will run out and move to ATMOS?
Are you willing to upgrade your PC to meet the new, very high specs you will need to process the speaker locations in real time?
I have to ask, how are you powering all those speakers without an external amplifier? You will need the at least 9 speakers to make this work (5.1 plus 2 front ceiling and 2 rear ceiling).
Cyberlink would be financially stupid to add Dolby ATMOS to their product just because a few people wrote they want it. It would take a corporate buyer asking for it (and one who is willing to pay the R&D costs of adding it) for it to ever appear. I cannot see that happening, ever.
If I were you, I would accept that PDVD will never have ATMOS because it is a stupid thing for them to add. I would go out and buy an AVR with ATMOS and DTS X support in it instead.