The Cult of Rapture has the promised (story) update on plans for the PC demo for BioShock (thanks BobtheCkroach). The apologetic post expresses regrets for failing a simultaneous release with the 360 demo (story), but expresses confidence in a PC release by the end of the month:

After the appearance of the BioShock Demo on Xbox 360™ last night, I’m sure many of you PC fans wondered, “What about us?”

Here’s the deal.

A BioShock PC Demo IS coming. We tried as hard as humanly possible to get it out to you guys simultaneously with the 360 demo, but we needed to make sure that it was perfect -- that all drivers were ready, and that the game looked great on a huge variety of computers.

Currently, the PC demo in its final stages of testing and approval. We are pushing to get it out to you as soon as possible. It will be out during the month of August, and everyone is working at full capacity to deliver it to you before the game hits store shelves on August 21st. I will also let you know as soon as I have an exact date for the demo's release, so please stay tuned.

I cannot express enough how sorry I am for the wait. Thank you for understanding and your patience. Just remember -- only eight days left till you get your hands on the full game.

I’ll let you know where to get the demo as soon as it becomes available.