While not TRS-80 related, it seems the DMK format is catching on. A French developer has written a command line utility to take DMK images of MSX disks, and convert them into a format usable by a SuperCard Pro device (which I suspect is something MSX related). Source is included if you want to have a look. The page can be found at http://lhalter.free.fr/mgr/
Also, the 80 Microcomputing Magazines
and the Model 100 from the below posts are STILL available for those able to do local pickup.