Or, it could just switch the default shell to Z shell.
First thing I do on a new Mac, is chsh -> zsh.
Ships with an up to date (enough) version of that.
It could, but "just" switching shells is definitely an inconvenience to your users as well.
zsh was even the default shell for an OS X release, 10.3 or 4 can't remember at this point.
Nope, before switching to bash in 10.3, tcsh was the OS X default.
Yep looks like you're right, I could have sworn that zsh was after tcsh then bash from there on out. Went looking in my Mac OS X for unix geeks book and it was right on the transition so bad memory no cookie. I'll punish my brain with beer for its transgressions.