Ok, Im not sure if there is a way of doing this already (in which case please tell me!), but
I sync some of my library with my phone using a smartlist. I find the smartlist and sync (with on the fly re-encoding) to be fantastic features of MC.
However, my stupid phone does not differentiate between multiple artist albums (e.g. compilations) and single artist albums or support the album artist field, so if I have a number of compilation albums, when I view by artist on my phone I see a huge number of random artists with only one or two track.
This got me thinking that a powerful feature would be something that allows you to set a remapping of the tags that are written to the files on the destination device. For example, what would solve my problem is if a rule could be established whereby the artist (auto) tag overwrites the artist tag if the artist (auto) tag contains something. Furthermore, I could set the track title tag to include the artist name instead for these instances, so the track artist info doesn't get lost, but navigation is far better on my phone.
Maybe I've missed something and this can already be done in the smartlist or some other way, but Ive seen a number of people with problems using playback devices that dont use tags particularly intelligently. A way of setting up a remapping of tags for the purpose of a sync would be an appealing way of working around these issues for any of the shortcomings that may be encountered on the destination device.