They need to update the slogan? "A command line shell for the 90s" doesn't really draw me in. What I want to know: 1. In what specific ways is it better than zsh? 2. Is it absolutely, rock-solid stable?
I'm wondering about the answer to #1 as well. After trying this out for a bit there's nothing obvious and there are definitely things I miss.
2. Breaking Bourne Shell compatibility. Personally I find Bourne syntax hard to learn and hard to read. Fish syntax is much better. [1, 2]
[1]: http://en.wikipedia.org/wiki/Friendly_interactive_shell
[2]: http://ridiculousfish.com/shell/user_doc/html/index.html