I brought this up a few years ago but figure it's time to try again. Any chance of getting the concept of different users added into MC? Being able to have different settings, play counts, smartlists, etc for each user would be nice. Currently I can approximate some of that with custom fields, but it's super clunky and doesn't work well with the interface (ie, I can make User1Rating and User2Rating fields, but there's no way to know which to display to the client). There is already the option for the client to log into the server, there would just need to be the ability to have multiple logins (and being able to specify view/edit permissions would be great). For display, something as simple as a filter to show all fields prefaced with "loggedinusername_" to only that user would be sufficient, although more complicated options would be great too.
I originally proposed using multiple POPM frames (
http://id3.org/id3v2.3.0#sec4.18) to track ratings on a per user basis within the ID3v2 framework, and I think that would still be awesome for music. In a multi-user setup, how often do all users consider all media to be rated identically to all other clients? The original paragraph applies more to video for me, but would work for both.
My basic use case is a house with an MC Server, 3 clients, and 2 users. Each user has their own client in their room and there is a 3rd client hooked up to the main TV/Audio. Client 1 is always used by User 1, Client 2 is always used by User 2, and Client 3 could be either.