It's like an Amiga owner being shown a "multimedia" PC in 1995 and thinking, I was doing all this 10 years ago.
Thing is ; these notebook interfaces COULD be really brilliant, but they suck and I don't know why. Maybe just not enough people working on them?
What many users of open source don't seem to understand is that actually, honest-to-goodness open source development is a major undertaking and imposition on a person's time. And quality software takes actual teams of actual people with experience and commitment and a basic peace-of-mind about paying their mortgage and putting food on the table.
This is why I love IPython on the command line. Language is nicer too and editing is a breeze. Of course Python and available libraries are not much of a symbolic computing environment, but for the kinds of problems I deal with its faster to get things done than in Mathematica.
I would definitely say that the smoothness of the Mathematica interface, the way it works and interacts currently would be a great thing for programming languages like Haskell. It's just clumsy the way it is now and this is not something you can help but it needs fixing. Let's discuss further somewhere!