There has been news that The Start button would be re introduced but it will take you to the Start screen.It would be better if Microsoft introduces the classic Start button. The Skydrive will be more tightly integrated in Windows Explorer. There will be news that Facebook and Flipboard apps will also be introduced in Windows 8.
You can find more detail on Windows 8.1 from the following link. http://www.techulator.com/experts/1437-What-Windows-8.1-new-OS-from-Microsoft.aspx