I took it to mean that it was a new type of shell from the perspective of unix/osx users who were presumably their target audience, and who are an audience who might either not know what PowerShell is about our discount it is just a "windows thing" and therefore not relevant to their life. So "new" in the sense of "new to you".
You could probably point to just about any technology that claims to be new and pull it apart and find that it is mostly derivative of existing technology and ideas
Sure, all work is theft, for some value of theft, but as I've said in a couple of other replies:
* "all these ideas have been done before, in various places" is one thing, "all these ideas have been done before in one program in the same role on all the same platforms" makes me feel like "new [to users who haven't used this other thing shipped with the OS for years on one of the platforms]" is insufficient to use without more explicit qualifiers
* I may be oblivious and missing some cool example, but the flip side to "all ideas implemented before" is "no new tricks", and when someone describes something to me as "a new type of X", I really expect at least one novel thing or composition of things to be present.
After all, I wouldn't describe TIFF as a "new type of image format" just because many people who haven't touched photo/graphics editing probably haven't encountered it, or IE4 as "a new type of web browser" (now) just because a significant fraction of internet users are not old enough to have used it when it had market share. (When it was first released, Active Desktop, for example, while a security nightmare, was indeed a new thing for almost all users.)
You could probably point to just about any technology that claims to be new and pull it apart and find that it is mostly derivative of existing technology and ideas