This video explains all. I've paid a total of less than $1 for payday 1 and 2 on ps3 so I've no problem shelling out $40 for this on ps4.
So its the same as the PC version minus a few content that will eventually come out and under 30 FPS but with 1080p ;o.
I'm glad Payday 2 is getting a lot of support - its a great IP that I'm glad is expanding - hopefully we'll see a true NEXT gen Payday in the form of Payday 3.