How come no progress has been made on this? It seems to have died, but this is an extremely useful, and pretty simple feature. I was able to find a LUA plugin that could impliment saving multiple presets, but it was really clunky. I tried the instructions here to overwrite some of the default presets:
http://www.stufinnis.co.uk/vlcequalizersave.html, but they didn't work for me (on Arch Linux). I have a friend who would like to have a custom preset that he can switch back and forth from (so he changes parameters, and then resets it to the custom preset), but other than the lua script I haven't seen any way to do this.