Confirmed memory and storage
Steam currently lists 8 GB RAM for the minimum configuration and 16 GB RAM for the recommended configuration. Both entries list 100 GB of available storage.
The operating system, processor, graphics card, sound card, VR support, and additional notes remain marked TBD on the listing.
How to check safely
Use the Steam listing as the source of truth and check it again near release. Do not turn the still-unpublished CPU or GPU fields into estimates.