Steam’s latest update adds support for Nintendo’s classic controllers that it makes for Nintendo Switch. Valve doesn’t specify exactly which controllers are compatible — the language in the patch notes is that Valve has “Added support for Nintendo Online classic controllers” — but the change presumably means you can now use the Switch-specific NES, SNES, Nintendo 64, and Sega Genesis controllers with your PC games.
If you want to pick up one of those controllers to use with Steam, you should know that you can only purchase them if you’re a Nintendo Switch Online subscriber. You can grab the NES and SNES controllers right now, but the N64 and Genesis controllers are currently out of stock. Nintendo’s website doesn’t indicate when they might be available again, but when they are, you’re going to want to jump on them quickly.
Fighting game fans might be happy to hear that Qanba’s Obsidian and Dragon Arcade joysticks and Hori’s Fighting Stick Mini 4 are now supported in Steam as well. And Valve has made some improvements in how Steam supports Sony’s DualSense controller: on Windows, you’ll be able to see a firmware update dialog (which follows the release of Sony’s official DualSense firmware updater app for PC), and controllers with updated firmware will have “improved rumble emulation” enabled.