Poweshell playing the same role as the workspace/transcript, which access to the whole system, including libraries and running applications. Specially given it is just yet another .NET programming language.
I am not aware of any UNIX shell that offers a REPL like capability by allowing to interact with system libraries, do IPC with existing applications or system devices.
.NET, COM and WinRT play a similar role as the rich programming frameworks Interlisp-D, Smallatalk and Cedar had.
Focus on a mixture of AOT and JIT code for the programming environments, with memory safe languages. Memory unsafe languages currently used on the lower levels and performance hotspots.
An IDE with graphical debuggers and incremental development support, as the main way to develop applications.
Focus on being a good workstation OS first, with server abilities as second focus.
"...even with the plus that is Visual Studio,... "
And you're touting things you value in VS.
I think that he poster was saying that for them the good parts of VS don't make up for other shortcomings of windows as a workstation...