>> To me, that makes good sense everywhere in Emacs.  Except I'd like `C-u
>> RET' to show a list of browsers, if I have more than one I like to use.

LMI> Yeah, that might make sense.  But is that a common use case?  I only use
LMI> Firefox for "real browser" stuff, and I don't really see why I'd switch
LMI> between Firefox and (say) Chrome on a regular basis...

For web development it's nice, but not a common case for sure.