Don't make this more complicated than it needs to be, observe:
http://news.php.net/php.internals
1) We already have a basic/simple web interface.
2) This could be extended to have the features of forum software
(threading, sorting, searching, voting, filtering)
3) All email posts would go to the extended interface, and all posts made
on the web interface would be emailed to internals (in the same text format
it already is in).
This offers the advantages of:
- Able to view topics and history at a glance, instead of everyone storing
the whole history set of internals (etc) in their inboxes
- Inviting to new people that don't want to use a communication platform
from the 1990s (and don't want the limitations of the above email
setup/management)
- All the old die hard email mailing list only guys still get the usual,
nothing changes (except hopefully more positive activity!)
+ many more, as the sky is the limit with the features that could be done
for the web interface.
I understand this is a hugely personal and subjective thing, but both would
be one and the same in the end, other than the web interface offering
hugely distinct advantages that email simple cannot do.