I've been asked by quite a few people about where to get more information about Windows Server 2008. My team is currently delivering a 24 Part Webcast series on Windows Server 2008. Some of the webcasts have already taken place and are now available on-demand. Others have not happened yet, so you can register to attend live and then download later.
Here's the link to the main page for the series: http://www.microsoft.com/events/series/windowsserver2008.aspx?tab=webcasts&id=42586.