WhatIf in Powershell also remains completely broken; not that it doesn't work, but it is not properly passed down the call stack like it's supposed to from cmdlets or functions written in PowerShell (as opposed to those loaded from .net assemblies).
I have seen it, I think it's because it's not easy to see whether the cmdlets or functions your calling support and support it right. It does work, but I have seen it not always work and that results in having to check or test every command. I think the GP is overstating the incovenience, though, and Powershell is still much, much better than any Unix shell in this respect (which simply has no mechanism and no standard way to discover one).
