Office 14 will have an online version – which can work seamlessly with the desktop version
This is the most important announcement which impressed me very much – Office Web Applications. Check more about this here. Embedded Video below:
Windows 7 – an inside look
Mark Russinovich talks about Windows 7, Original link here, video below:
Inside Live Services – David Treadwell
When Windows Azure has already made news, it is interesting to watch this video where David talks more about the Live Services.
You should also check this post from the Live Mesh team which talks more specifically on Live Mesh.
Windows Server 2008 R2
As Oliver outlines about this on the team blog, Windows Server 2008 showed its face at the PDC2008. Check the below links for more:
Hope this helps!