What's the status of this feature? I have an appliance device that advertises SFTP service on my network. It would be really nice to recommend this client for my customers!

Thanks in advance.

Thanks for your suggestion.

This request has been added to the tracker:
Issue 947 – Support for Zeroconf/Bonjour

SFTP servers can "advertise" themselves on a local network using Zeroconf (aka Apple Bonjour), using service type _sftp-ssh._tcp. It advertises details such as hostname, port number, and path. Then SFTP clients can find them, and display them for a user to connect to without having to type in the details manually. It would be great if WinSCP could support this.

It depends on Apple Bonjour being installed on the PC. This could be an optional dependency, or bundled in the WinSCP installation package. See:
https://support.apple.com/en-us/106380 (user installation package)
https://developer.apple.com/downloads/index.action?q=Bonjour%20SDK%20for%20Windows (SDK)