Many email clients already support interacting with NNTP servers. IIRC, Windows (Live) Mail, Outlook Express, and Thunderbird all support reading email as well

Many email clients already support interacting with NNTP servers. IIRC, Windows (Live) Mail, Outlook Express, and Thunderbird all support reading email as well as newsgroups. IME, it's no different than using email other than the fact that you'll have a Newsgroups field instead of a To field. Composing and replying are pretty much the same as email. And each subscribed newsgroup could just as well be thought of as an email folder.