Windows Server 2008 has been launched at 27th of Feb. After a long adoption phase has finished at RTM date, SAP's plans to support Netweaver 7.0 based on the Web Application Server 7.00 on Windows Server 2008. The current state os described at SDN at https://www.sdn.sap.com/irj/sdn/windows. There is also a SAP note 1054740 which describes the technical requirements to install a Web Application Server on W2K8.