I'm still keen too! I've noticed a few features that aren't entirely unicode compliant; exporting playlists, for one (other than playing now). While I understand that certain playlist filetypes are not traditionally meant to be unicode, I'm pretty sure that some programs will read it if it is regardless, and it might be useful for such an option.
Especially since for my mobile devices, I use .m4a, and because of this, use an external encoder. And because of this, the .flac filesizes are used to measure what will fit on the external drive, and so instead it's easier to have a playlist within the player, but export the playlist and use a different one to convert the files. .. only, I can't, because I have unicode filenames and folders, and the program won't read native filetypes to MC/MJ!
There are other peculiarities, like the fact that the toolbar mouse over does not display unicode, as well.
If any of these codes are not within the right for JRiver to alter, I am surprised they are still released with the software! (At least, I didn't think I'd downloaded plugins... Maybe I forgot..?)