Just a quick official word...
5.7.0 will release on September 12th.
This will be a stable production ready version of 5.7, with no marketplace integration. We're getting it out there for our add-on/theme developers to build towards knowing nothing major will change. We also want our larger clients who may be solving their web challenges with the core and custom code more than the add-ons/themes we sell to be able to start working on their big projects with 5.7 sooner rather than later.
22.214.171.124 will release on September 30th.
This will include marketplace integration, bug fixes, and whatnot. We will be working frantically on docs during this period as well (editors guide has already started coming together) so expect that and some more site improvements here to support the maturing ecosystem..