Windows 8.1 A.K.A blue is official

Microsoft just announced the windows 8.1 A.K.A Blue by the Corporate Vice President of Microsoft, Tami Reller and it will be available for preview to the public by the last weeks of July or or first week of August (depends upon the country I guess) and it will be available thought the store for FREE, but the final build has no final release  date yet.

But the change log of this said update is still unknown by now and will be announced by Microsoft  sometime later .