Microsoft kicked off with its early Build keynote today, where they announced a number of new features coming to Windows Phone 8.1 such as notification center, cortana, and much mroe. They also talked about news coming to Windows 8.1 update 1 including showing of a new start meny which is coming (Not now but later)
Update 1 will be available for the general public at april 8th, but is available now on MSDN.
This update is both for Windows 8.1 and Windows Server 2012 R2 ( And consists of a couple of patches)
So there are a couple of new features which are pretty obvious.
Highligthed apps, shutdown button more visible.
Enterprise mode in IE (Needs to be enabled in GP)
Now give it a try!
ill come back with more when I have tried it on Windows Server as well!