I would simply like a forge mod that had both a server and client part, for the sole purpose of being able to change the name displayed above the head of a player without affecting the player's skin.
If it were possible to make this mod work with an existing bukkit plugin (for couldron servers) so that when the name was changed with that plugin, it would also change the player's name-plate, that would be most preferable, as I like to use that particular plugin for giving custom chat names (primarily because it allows spaces in the players' names).
If it has to work with its own server-side mod/plugin, that would still be fine.
Spoutcraft, when used with the spoutplugin, is able to do this very thing, but the client itself is pretty much incompatible with any forge mods.
Also, I'd plan on using this for a role-play server, so it might be nice to have an option to make the nameplates faded and invisible through walls (as if you are sneaking, but without having that awkward animation of being permanently crouched over) to cut down on meta-gaming.
(I personally don't know anything about coding with java, so if please forgive any ignorance to obvious reasons why this wouldn't be possible, if there are any)
I've tried using plugins to get a similar effect, but the fact that actually changing the nameplate removes your skin is very bothersome. A client mod that could make the plate only appear to change would help a lot in that area.