A fair number of my apps are still 32-bit—see how many you still have—though many I don't really care about all that much. But there's one suite of apps that I use every day, usually multiple times a day: Fujitsu's ScanSnap apps. This is the software bundled with the ScanSnap ix500 scanner.
While Fujitsu has been good about updating their software in the past, I was a bit concerned about the upcoming 64-bit transition. So I both tweeted at them and sent them an email. I haven't seen a reply on Twitter, but a (clearly form letter) reply to my email is at least somewhat encouraging:
There is no problem in the behavior of the application or the OS concerned. The message is only inform that the application needs to be modified for compatibility with next-generation macOS (which should be available near the end of the year). PFU is going to resolve this, but the resolution date is not set yet. In the meantime, please continue using the latest version of the software available.
This blurb was obviously prepared as a response to those complaining about the new 32-bit warning dialog in macOS 10.13.4, but it does seem to address the longer-term question: Fujitsu is planning to "resolve this," which hopefully implies 64-bit versions are in our future, though at some not-yet-disclosed date.
There are very few things in my workflow that I couldn't replace…but replacing my ScanSnap and everything it does for me would be quite difficult. Hopefully we'll see a 64-bit ScanSnap suite before this fall's deadline.