Microsoft is developing a command line environment, which they call PowerShell. I read some negative feedback, but it looks rather interesting and powerful. The main difference from traditional Unix approach is that the commands do not communicate via standard input/output channels, but rather export and consume objects with properties. These properties can be queried and eventually actioned upon.
The current release candidate uses .NET Framework 2. It would be very interesting to see a port to Unix - a lot of ready code can be extracted from currently existing Unix tools. Maybe an open source project will start to create such a port.