UPDATE 4th Sep 2015: Warner Bros. has released the Batman: Arkham Knight PC patch properly this time.

The promised "interim" patch is now available to those who already have Batman: Arkham Knight for PC, while the game itself remains off sale.

Here are the patch notes:

Reduced frame-rate hitches.

Optimisations for system memory and VRAM usage.

Improved performance on all GPUs (requires the latest drivers).

More comprehensive in-game settings.

Fixed low resolution texture bugs.

Fixed hitches when running on mechanical hard drives (HDD).

Meanwhile, Warner said it was continuing to work on improving the game for future updates. Here's what's coming next:

Adding support for SLI and Crossfire.

Adding support for the latest DLC and Season Pass content.

Adding support for additional updates such as Photo Mode.

Continued improvements and bug fixing for a Windows 7 specific memory issue that occurs on configurations with 8GB of system RAM and some Nvidia GPUs during extended game play.

Continued improvements for Windows 10 specific issues on systems with some AMD GPUs.

ORIGINAL STORY 3rd Sep 2015: A patch for the much-maligned PC version of Batman: Arkham Knight was released overnight, before being pulled shortly after.

Image courtesy of Steam user AMorassOfPixelz.

The patch, which was released to those who opted into the beta version of the game on Steam, makes important improvements to the performance of the game, according to those who managed to test it.

Steam users report improved and smoother frame-rates, as well as more graphics options.

Warner had promised to release an "interim" patch in August for the PC version of Rocksteady's game, but that failed to materialise. Perhaps this update is that patch, in which case it looks like it's nearly ready.

Currently the PC version of Batman: Arkham Knight remains off sale.