I don't think that Usenet NetNews and LISTSERV provide the same service
 to their users.  Yes, there's some overlap, but to suggest that moving
 all your LISTSERV functionality to Usenet will provide equivalent
 services isn't accurate.  They were designed with different goals in
 mind.  And also if talk, mail, etc... provided the same functionality as
 "tell", then there wouldn't be an ongoing effort to develop and implement
 the "Message Send Protocol" on the Internet.
 
 -jj
 
 PS - It might be of interest to note, that one of the problems that has
 come up in implementing IP based "messages" is authenticating the origin
 of the message.  That is, aside from bad emulators that let users do
 nasty things they shouldn't, the NJE model provides a trustworthy message
 facility.  It's not as easy to do the same over the Internet.  There are
 very few things that can be described as simply black or white.  Most
 complex systems, like Bitnet, Usenet and the Internet, are inherently gray.