When I hear Walkman I only think of cassette tape, not MD, but whatever... Minidisc understandably gone away (until maybe hipsters revive that too like they have with tapes?) but on the tape front ... Maxell thinks they have something with cassette players.... wonder if/how these are selling: Maxell MXCP-P100 – wireless cassette player https://news.ycombinator.com/item?id=47497781
That is already happening. I like to frequent Vintage Computer Festival and for the last few years a few of them have had MD-Con as part of a convention within a convention. A whole room dedicated to MiniDisc tech showing off laptops, desktops, camcorders, pro-hifi gear, etc. There is a collector that even brings a large portion of his collection which is all in blue including rare blue color minidiscs themselves from company promo's. One example is a promo MD from Boss Coffee in japan which looked fantastic.
There is even a revival in the software used to burn/format minidiscs since most of the original software is ancient now.
Its pretty fun to visit them as someone who used a minidisc player through highschool and college until I got the original Microsoft Zune. A lot of the people I met at the last two MD-Con's loved looking through all the models presented at the con to try and find the same device they back in the day.