With development already at a year for the remastered PS4 version of the game, the big thing we can expect according to the development team is graphics that have been turned up all the way to 11. Draw distances are farther, improved shadows, better lighting, and of course much improved and higher resolution character models.
The biggest reason to do this is because the fans wanted it and as a result the studio says that they have doubled down and put maximum effort behind the development of the remastered edition of the game for the PlayStation 4. The remastered edition of The Last of Us will arrive for PlayStation 4 owners this summer and will include all of the major released DLC for the game.