Looks like the internet spoke a little too soon when we all reported that the RTM (release-to-manufacturing) build of Windows 8 would likely become Build 8888 just a few days ago, as according to WinUnleaked, Microsoft has just yesterday compiled Build 9200, which has become the new internal RTM candidate.
Windows 8 Build 9200 reportedly includes a new default wallpaper and, presumably, bug fixes and improvements over previous RTM-candidate builds of Windows 8. The last publicly released build of Windows 8 was Build 8400, the Windows 8 Release Preview.
Build 9200 is likely to also be the final build for both Windows Server 2012 and Windows RT, the Server and ARM variants of Windows 8 respectively. Windows 8 is set for release on October 26th, 2012.