Microsoft has formally announced that Windows 8.1 will be available as a free update for Windows 8 clients via the Windows Store starting on Thursday, October 17, 2013 at 7am (local Trinidad and Tobago time)
You can still download and evaluate Windows 8.1 Preview at http://windows.microsoft.com/en-us/windows-8/preview-download
Here’s a video from Microsoft outlining the key changes of Windows 8.1 Preview (and presumbly still in Windows 8.1)
http://youtu.be/VQb5caeSo00
