Ok, I have heard questions about this, so I'll answer here. We will do a community mod for a27, however there will be changes to how it works.
In a26, we had issues where the mod would split the multiplayer community into mod players and non-mod players. Also, because the mod fixed a couple of bugs, development on the mod was a constrained by the requirement that each change be a clear improvement. This hampered experimentation.
So the main change will be that each community mod version will be a clean slate, no changes from the last version will remain. What this means is that the mod serve the purpose of a "Community Test Environment", or CTE. Essentially, its a way for gameplay-oriented changes to be run by the community before being committed to the development version of 0ad.
My hope is that we can make release turnaround fairly quick, and test a lot of ideas. Players can certainly continue to submit PRs, but I'd like to invite developers to submit their gameplay-oriented PRs too.
Some stuff I hope to experiment with:
capture vs destroy balance
walls delete trees
3x cavalry counter
added economic unit to address boom = turtle
ship balance
Improve Han gameplay