Microsoft has compiled a beta build 8180 of Windows Server 8 on January 9, as indicated by the build string: 8180.0.WINMAIN.120109-1245_X64FRE_SERVER.
PCBeta and WinUnleaked posted a few screenshots the build 8180 showing off that the Server Manager dashboard has been updated that replaces the white theme present in the Developer Preview, with a dark metro theme.
WinUnleaked also shows a new logon screen present in the Windows Server 8 Beta. Again, not much has changed here and the overall theme is darker.
WinUnleaked also had managed to snap some screenshots of the Storage Spaces feature working with the new ReFS Windows filesystem.