So, noticed that installing the Enterprise version of Windows 8 RTM it never prompts for a key. However, once installed, the client won't activate and says
Error code 0x8007232B, DNS name does not exist.
In looking at the license key, it shows a key that ends in CWCK7. (but of course, remember I didn't input a key)
It appears that enterprise is pre-baked with a KMS key, but unlike Windows 7 there is no button to "Change Product Key".
You have to get elevated command prompt and type
slmgr.vbs -ipk "Your key"
That seems a bit strange.
Where I got the above info;
Windows 8 RTM - Enterprise Activation