It essentially brings the PS4 version up to par with the current PC version. I assume there will be an announcement and changelist once the Xbox One version is also live.
I have seen a few posts on here where people have been having problems related to selling too many items to merchants (over time) causing some kind of error with loading the game. This seems to be addressed in the patch.
I would still very much like to see a list of changes specifically addressing the platform I play on (PS4) please.