After playing the tutorial mission in GTA V on PS3, i noticed that it's stuck @ 576p .. this is ridiculous, i knew something is wrong. Then i googled around a little bit about GTA V being stuck on 576p resolution and found out that GTA V on consoles is not meant to run 1080p at all, it doesn't even have textures for 1080p, it only runs @ 720p max.
But problem with 576p is that PS3 does not have all options enabled by default, simply quit game and do this:
Settings > Display Settings > Select all options (576p / 720p / 1080i / 1080p)
Note that on my 42'' LG TV im having issues with 1080p (i have to use 1080i), 1080p has some artifacts and sound glitches going on, no idea why, so i left 1080p out. This is NOT because of my TV, its maybe 2 years old model and it support 1080p easily, i use that tv with my media station PC and its set to 1080p, works great, so its some incompatibility between PS3 and TV, anyway 1080i works perfectly, so for GTA V you must include 720p or it defaults to 576p and looks like super shit.
Hope this helped.