Over at the Wilders Security Forums, David has posted a roadmap, some time ago.
This here is just a copy with items left to implement:
add missing virtualization to EventPair & KeyedEvent objects
add filtering and virtualization to Timer objects
add support for EFS using the user proxy available in insider build, scheduled for 1.15.0 requiring a standard certificate
add break out document functionality available in insider build, scheduled for 1.15.0
Better UWP support, in compartment mode...