If a list of trophies are any indication it looks like Bethesda is prepping a Doom collection that contains the original, Doom 2, Final DOOM: TNT Evilution, and DOOM: Plutonia Experiment.
Here's the list - http://exophase.com/game/doom-classic-complete-ps3/trophies/
Here's the list - http://exophase.com/game/doom-classic-complete-ps3/trophies/