I get the occasional query as to what is new in PowerShell 4. For the most part, the key update is the addition of Desired State Configuration plus a bunch of bug fixes. But there is a lot more, as you can see in the What’s New help file: http://technet.microsoft.com/en-us/library/hh847833%28v=wps.630%29.aspx?_=1385725589770.
The biggest new feature is DSC, desired state configuration. DSC enables the deployment and management of configuration data for software services and the environment in which these services run. DSC is a great feature, but as it stands in V4 is not really complete. It needs more work, and specifically needs some tooling to make specifying DSC easier and a lot more straightforward. No doubt this is coming in V5 – we’ll see.
In addition to a number of new features, V4 brings a bunch of bug. Interestingly, the bug fix I like most is not mentioned: In V3, CIM based cmdlets (cmdlets defined using CDXML) did not properly add the noun and verb to the command’s System.Management.Automation.CmdletInfo object. That is now fixed.
Sadly, V4 does not run on Windows 8 which many continue to think is daft. But the folks in Redmond clearly know more than I do about this stuff and there must be great reasons. Given that PowerShell V4 runs on Server 2012, it should run just fine on Windows 8. For me, this means I can’t take advantage of V4 on a couple of machines as I just do not have the time to downgrade to Windows 7 or upgrade to 8.1.