Windows Server 8 new remote Access Server role combines the previous DirectAccess and RRAS roles into one unified service role. The new role allows for centralized administration, configuration, and monitoring of both DirectAccess and VPN-based remote access services. Apart, from the various articles and tech tips available at windowsnetworking.com and virtualizationadmin.com you can learn more about Remote Access in Windows Server 8 beta, by downloading the draft version of Microsoft's Understand and Troubleshoot Guide (UTG). The guide enables you to learn about technical concepts, functionality, and general troubleshooting methods for new Windows features and enhancements.
Download the Understand and Troubleshooting Guide from here - http://www.microsoft.com/en-us/download/details.aspx?id=29004