On the Symfony Finland site there's a post that gets into the details of one of the new advancements in the Symfony ecosystem recently announced by Fabien Potencier at SymfonyCon Berlin 2016 - Symfony Flex.
The Symfony team has acknowledged this gap in their offering. And at SymfonyCon Berlin 2016 project lead Fabien Potencier announced what is known as Symfony Flex. Details are not precise, as I was not attending conference, but the tag line for Symfony Flex is: "Composition over Inheritance"
In essence it seems that Flex will allow for zero-config installation of Bundles. This is done using a Composer plugin. You will simply install packages with Composer and if the Bundle supports it, Composer will also author the necessary integration code and configuration.
As with any new thing, Flex support will start out pretty limited but as it grows in support the community should help it thrive in the Symfony ecosystem. The first release of the tooling for Flex will be available in early 2017.