Have you used Microsoft Powershell? It (indirectly) does a useful portion of what you're dreaming about. It's a UNIX like shell where commands pipe .NET objects instead of plain text. Just like UNIX commands take and produce arbitrary text but most think of it as a sequence of lines, Powershell commands can take and produce arbitrary .NET objects but most use an object which is a collection of records.

Powershell comes with builtin commands for most of the simple UNIX utilities, and you build new commands in any .NET language. Additionally, you can interop with UNIX style programs that produce plain text by using a parsing filter (there are a few builtin, you can make more).

It's actually pretty good and a lot more regular and modern-feeling than any UNIX shell I've tried. I still prefer to use GNU/Linux, but wish there was a good port of Powershell...