I just saw that Visual Studio 2013, Team Foundation Server 2013, and Release Management all have Update 4 Release Candidate available. You can read all the juicy details in KB2994375!
The Release Management stuff looks exciting, although I haven't had a chance to sit down and play with it. Here's a copy-and-paste!
Use tags when you deploy to a vNext environment
Now, you can use tags together with the servers in your vNext Azure or standard environments. When a stage is deployed, these actions are performed on any server that contains this tag. Therefore, you have to create the set of actions only one time for multiple servers. By using vNext tags, you can also switch the deployment order from parallel to sequence.
Access to system variables for your deployment sequences or scripts
By popular user demand, you can now access system variables in the same manner as other configuration variables and you can use them in your release template. You do not have to hardcode these variables any longer.
Reduce the need for configuration files to deploy your builds
You can now set up configuration variables for your release at the global, server, component, and action levels. This additional flexibility means that you may no longer have to maintain configuration files together with your build.
Manual intervention with a vNext release path
Now you can add manual steps to a stage in a vNext release path, and you can add a manual intervention activity to your deployment sequence. When the notification is triggered in that sequence, the deployment pauses, and then you can run some manual steps before you continue to process the rest of the automation for the release path.
Build drops that are stored on TFS servers
If you have set up your build definition to copy the build output to the server and not to a UNC path, vNext components in Release Management can now use the builds that are stored on the server.
Deploy from a build drop by using a shared UNC path
Now you can use release management to deploy to servers by using build drops that are located on a shared Universal Naming Convention (UNC) path. You can deploy if both the target server and the Release Management server have access to the shared UNC path.
I haven't had a chance to write anything up on using Desired State Configuration + Release Management yet, but it's definitely an interesting area.