On the other hand, it would be convenient if we could quickly upgrade
to the latest ConTeXt on a Mac.
ctxtools --update
gives me
unable to fetch cont-tmf.zip


same here (OSX 10.4.9)

Maybe you are behind a firewall?, we discussed this on the list earlier this year. (BTW upgrading will break XeTeX :-( but maybe you don't mind.

Gr,

Jelle