PowerBuilder 12.6 is now available on the SAP Marketplace, with the same features as the beta provided earlier this year.
Note that when moving to PB 12.6, you will have to migrate your code because it was built as a major version.
Official announcement available on the SAP SCN PowerBuilder Developer Center.
Note: this version of PowerBuilder is no longer available
Since then, Appeon added lots of important features.
You can learn more about the latest version of PowerBuilder or get a trial on the Appeon Website