Let me discuss my powers and limitations. As of right now, I'm still technically on the Proving Grounds team, though our post-release support is currently "limited", seeing as how the patch unfortunately borked. I'll be moving more formally to live design next week, which will functionally not mean much different for my day-to-day operations other than that I get trolled by Geeves a lot more.
On the Dominion side, what I am actually doing is scouring for actionables and sorting them into a priority list. I'm also trying to actually PLAY a lot of Dominion, because I have a rudimentary understanding of competitive Dominion minutiae. At top priority are tasks I can personally accomplish as a designer: number tweaks, slight mechanics changes, non-programmy stuff. Next are tasks that would primarily require designer time, but also require external resources such as art in the final stages: possible brush position shifts, new items, etc. Finally, there are long-term tasks that require potentially lots of people. For example, the score system overhaul thread has potential changes that will require me, tech designers, artists, and possibly UI dudes.
Then there are out-of-scope issues. I can sometimes inquire, but may not be able to drive them. Competitive exposure, marketing, ranked queue, IP/XP rewards, etc.