A pair of ESRB listings reveals that Rockstar plans to re-release Grand Theft Auto III and GTA: Vice City for PS3 in the near future. Based on the listing, it seems the games won't be graphically improved: The games are listed as two separate games, so they won't be as a single bundle.
The listing first appeared on the ratings system in January, but dropped of the radar until this week, according to Eurogamer. Based on the postings, it's possible that the re-releases will hit stores sooner rather than later.
Grand Theft Auto III was released for iOS and Android in December. Vice City is celebrating its own ten-year anniversary this year, having first reached stores in 2002. Presumably the re-releases will help stir up renewed interest in the franchise while fans await the release of Grand Theft Auto V.
Rockstar has yet to confirm the existance of any plans to release either game for any new platform.