NeoGAF, where all the gaming news breaks, has struck again. User ULTROS! has spotted the original Grand Theft Auto 1 and 2 on the US ratings boards. Both games have been rated by the ESRB for the PlayStation 3, PS Vita and PSP platforms, with GTA1 receiving a 'Mature' rating, and GTA2 getting a 'Teen.'
Considering the other GTA games, except GTA4, are on PSN, it would make sense that developer Rockstar would be re-releasing games as Grand Theft Auto 5's release approaches; that said, they still haven't mentioned any of these plans.
The likely scenario is that the two games are released via digital downloads through the PlayStation Store.