The latest stats from TheCounter.com show that NS4 now has only 2% of the browser market share, with IE5 and IE6 between them having 91%. (Although admittedly TheCounter's stats aren't necessarily representative of the entire world, and in fact don't quite add up due to the way they've rounded the percentages! lol)

This article says it all:
http://hotwired.lycos.com/webmonkey/...l?tw=authoring