Batman: Arkham Knight will have a day one patch on Xbox One, PlayStation 4 and PC. Now, normally i wouldn't even mention it. But this is a 3.5 GB Patch it seems. 

It seems like some retail copies of Batman: Arkham Knight Day One patch has been leaked as some users on Reddit have started posting details and screenshots of Day One Patch. Batman: Arkham Knight Day One Patch "1.01" will weigh 3.527GB and will carry following improvements and bug fixes:

- Improved Performance
- Stability Fixes
- New feature: Rival Points
- New feature: Original Batsuit skin available to select
- Support for "A Matter Of Family" additional content*
- General gameplay, graphical, audio, UI, and localization fixes 

* A Matter Of Family is a prequel story DLC which is included as part of Batman: Arkham Knight $40 Season Pass.