Please note that the Salesforce DX was previously in Open Pilot for some time and then through last few months it was in Beta. Even in Beta phase it was quite stable.
Customers can enable Dev Hub on their production org or if they want to try Salesforce DX, they can register for a trial dev hub org through this link
Once registered the users can download the CLI tool (https://developer.salesforce.com/tools/sfdxcli )and use it to do development, create scratch orgs, push and pull source code from these scratch orgs.
Developers can also use it to deploy and retrieve metadata from Sandbox and Production orgs. They can even use it for destructive deployments for deleting metadata from the orgs.
Visual Studio Code is now officially supported Text Editor instead of Force.com IDE which is not very surprising for most developers as Force.com IDE which is eclipse based in very challenging to work with.
The Visual Studio Code editor has nice code completion feature implemented using Apex Language Services. Syntax highlighting for Visualforce and HTML code is supported.
Since Salesforce DX CLI tool can output json it is very useful for chaining of tasks and scripting in CI/CD Tools like Jenkins.
We have created several videos on Salesforce DX. Please visit our channel to find out more.Here is the link
Some important videos from our channel
Destructive Deployment using Salesforce DX CLI
How to use GIT and Salesforce DX commands in VSCode
Salesforce DX Secret - Where does Salesforce DX store changes in the org
Bulk Data Load using Salesforce DX CLI
How to install and configure VSCode with Salesforce DX
Salesforce DX and Jenkins Series