Remember, you read about it here first!
Although if you go to the Official DirectX page on Microsoft's server here, you will see that its still version 8.1 thats available, Microsoft have indeed placed the final build of DirectX 9 on their servers and its available to download here. Please note that this is a web based installer, and not the self-contained distribution of DirectX which is around 9MB I believe.
In case you are wondering how I got the link, it was from here.
I imagine that an official announcement will soon be placed on Microsoft's main page here and on the Official DirectX page here.