Mapping split ${(s::)...} across an array

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

I recently had a situation where I wanted to create a new array by splitting
every element of an existing array.  The only solution I came up with was
to first join the original array into a string using the same character I
wanted to use to split the individual elements.

Is there another way?  :s// and similar replacements are mapped across an
array by definition, but that doesn't help (does it?).