Hot off the press! http://wiki.dlang.org/Vision/2016H1 -- Andrei
For PRs, I suggest the goal to be number of PRs MERGED instead of created. That may provide the core team a subconsious incentive to look at long pending PRs and hit a good cycle.
For tooling, I suggest a look at GUI/IDEs, now that dlangui/dlangide seems a good candidate(native D, crossplatform). A good official supported GUI library will attract many people.