The press release is ambiguous about the PC version, but seems to suggest it’ll be available for everyone through Steam from 1 August (here’s the exact wording: “The Windows PC version will be made available through Steam on August 1, 2012”). Whether that’s still only for those who pre-order is unclear.
In addition, the game’s release date has been confirmed as 20 November.
Enjoy the sniping trailer, below. Say … is that Ezio at the end?