OK IT Pro’s fire up your browser and go grab the version of Windows 8.1 you have been waiting for to prepare for your organizations transition to Windows 8.1.  Of course you do need to be TechNet and MSDN subscribers to get the RTM bits.

Erwin Visser just posted on the Windows for your Business blog about the availability of the RTM version of Windows 8.1 Enterprise.

Beginning today, TechNet and MSDN subscribers will now have access to Windows 8.1 Enterprise RTM. This also includes access for Volume License (VL) customers with an active Software Assurance (SA) agreement, as you receive a TechNet subscription as part of SA.

The other thing Microsoft is providing plenty of is tools to help you prepare for your own migrations to Windows 8.1:

As business customers evaluate versions of Windows 8.1, we’ve just posted an updated feature grid comparing the Windows 8.1 Pro and Enterprise SKUs for reference as you’re evaluating Windows 8.1 for your business. That said, we strongly encourage business customers to evaluate Windows 8.1 Enterprise, which supports the premium features designed to address the mobile productivity, security, manageability and virtualization needs of enterprises. For all devices currently running Windows 8 and for those of you who are testing Windows 8.1, use Windows 8.1 Enterprise RTM as another opportunity to evaluate the operating system so you can start your official migration when Windows 8.1 Enterprise GA becomes available on October 18.

It also looks like Volume Licensing customers who received Windows 8 Pro through a VL agreement will be authorized to use that same volume license for Windows 8.1 Pro even if their agreement has already expired or will expire before GA on 18 October 2013.

However, Enterprise customers will still be required to have an active agreement to use Windows 8.1 Enterprise.