Ok, so it's been four years, and I return to tackle this problem again.

I wish to allow the people in charge to modify greeting messages, without intervention, as we can not manage the work load when holidays come around, seemingly very often!

I find my self stuck between a rock and a hard place:

Option 1) I could use a virtual ext as the message, and users could easily logon as that ext and upload, or indeed the could log into that ext voicmail, thorugh the auto attendant and using "*0".
But Voicemail boxes have no "Greeting Only" option: i.e VM message plays, but VM option is not available. (NBX system have a simple concept: "Greeting only Voice Mail box"

Option 2) To resolve the Greeting Only problem, I can use a simple AA scenario.
But I do not see how to acheive user control over this message.

Please, anyone has ideas?

Someone must have pushed out a similar solution within the last 4 years...