This looks like a very good start on a useful feature.
As some others have said, the #1 resource column seems a bit dubious. How is it being calculated/weighted at the moment?
I could see this screen being of immediate usefulness when a new tech is researched. Then I could go to the city list view, pick out all the cities that could use the unlocked buildings/units, and then immediately build them.
To that end, it would be great if:
-We had the ability to choose/change column headings. If I want to see where all my crystal/arcane/tech/metal is being produced in the city view, I'd like to be able to change the columns to do this.
-It would be great if we could call the city build/train dialog boxes up directly from this menu, without being dumped from the list menu into the main gameworld.
-The minimap was functional enough to indicate a city that you have highlighted in the city list window (flashing, different color, etc.). This would help us know if we should be worried about that 0 in the defense column. If the city is miles away from the front, that might not be an issue.