The public focus of Windows 8.1 has been on the Start button: Is it coming back, is it like it was, and so on. (The button is coming back, but only as a toggle between the Start screen and the Desktop; there is still no Start menu.) That issue aside, there are other important aspects to Windows 8.1 you should know about, and most of them are in the Enterprise edition, which is available only through Microsoft's Software Assurance progam for businesses.
The standard edition of Windows 8.1, which will be on many PCs sold to individuals, doesn't allow domain joins or support PC control via Group Policy. But the Pro edition supports these Active Directory-based capabiltiies, as does the Enterprise edition. And Windows 8.1 Enterprise has many cool features IT admins will love. See my list below.