Following the option to connect your Steam and PSN accounts introduced in Marvel's Spider-Man Remastered with patch v1.1006.0.0, there is now a dedicated page on PlayStation.com for Steam to PSN account integration. Incentives to do so include unspecified unlocks in games made by PlayStation Studios, Sony's first-party roster of game developers.
Link your Steam Account to PlayStation Network to receive unlocks in this and other PlayStation Studios games. You will also receive the latest news, updates, and offers from PlayStation Studios games on PC or PlayStation platforms. Register by creating a Sony account for PlayStation Network or by signing in with your existing Sony account and password. For new accounts, you may opt-in for email and console messages when creating your account. For existing accounts, opt-in for messages via the "Notifications" tab in your Account settings.
Connecting your Steam and PSN accounts will be done directly in the games. Sony also provided a brief FAQ to explain how the procedure works:
What are the benefits of signing in to PSN on a PC?
By signing in to PSN on your PC, you are able to access unique bonus content, manage your communication preferences, and receive the latest news, updates, and offers about your game and other upcoming PlayStation Studios games on PC or other PlayStation platforms.
Do I have to sign in to PSN to play a PlayStation game on PC?
Signing in to PSN is optional when playing a PlayStation game on PC.
Do I have to sign in to PSN for each PlayStation game on PC?
No. Once you have synced your account for PlayStation Network for one game, it is synced for the other PlayStation games on PC. If you unlink your account, it is unlinked for all games.
There's no explicit list of games that offer the Steam - PSN link feature, but the featured image shows Days Gone (released about a year and a half ago on PC), God of War (launched in January 2022 on PC), and Uncharted: Legacy of Thieves Collection, due to launch on October 19th on the platform. That's in addition to Marvel's Spider-Remastered, which was the first title to receive support last week.
Of course, other PlayStation Studios games are available on PC, such as Horizon: Zero Dawn Complete Edition, the upcoming Sackboy: A Big Adventure (due on October 27th), and Marvel's Spider-Man: Miles Morales (planned to launch this Fall). Even more are rumored, chiefly Housemarque's Returnal, and PlayStation Studios head Hermen Hulst just teased further investments in growth spaces like PC, mobile, and live service games.
All of these games are available on Steam, being by far the main PC platform. Now, whether there will be any exclusive unlocks for connecting PSN and Epic Games Store accounts remains to be seen.