[recipient list trimmed]
I don't understand what multipart/choices is for. There are
implementation problems for multipart/alternative, but they
don't get fixed by proposing something new. They can (and
should) just be fixed asap, which is easier than to implement
something new.
I would further argue that "something new" in this space which is
so similar to multipart/alternative serves merely to increase the
number of implementation options, and thus, to decrease the
liklihood of interoperability.
Keith