Give KMS an easy to use GUI and make it a no brainer to setup and maintain.
KMS is annoying and provides no value to the customer, only to Microsoft. It should be made drop dead easy and flawless so admins have to spend virtually no time on it both for installing and maintaining it.
KMS should definitely be a role. You'd want to ensure that a KMS server didn't accept authorisation attempts before having the keys configured so maybe the servers could be authorised like DHCP servers.
Perhaps there could be the option for the keys to be stored in AD in those environments.
However it is done, get rid of that VBS script! A good starting point for me would be to replace it with PowerShell CmdLets
With the current way KMS Servers are deployed I end up seeing rouge/misconfigured in half the environments I consult with. Someone always tries to activate Windows or Office and turns their desktop/server into a KMS server by accident. Let's just make it a role with a basic GUI that shows you what Keys you have, activation status, count, and other basic info.
Kevin Gould commented
It should also provide basic statistics on all the products in a readable fashion - Office is a good example. Also eliminate this driving need to either patch or completely upgrade the OS of your KMS every time it needs to license a new product. It's compete nonsense that this is necessary. It's a debacle every time a new OS ships. It should be a new key - end of story.