Microsoft Office 2010 :
Microsoft Windows 8 contains deadly features. They may included Office 2010 in windows 8
For the better performance to offices they may included inbuilt in windows 8 ( Windows 7 final build 7700 )
Windows Live Messenger 2010 :
The other windows feature in windows 8 is windows live 2010 messenger. Because now a days system ranges increases, people wanna new features and updates. For that purpose only its may also included in that build 7700.