Given the complexity of creating an AI for a game like TripleA, the current hard AI performs quite well, especially on a tactical level. I often play 1 country and let the AI take the rest. This generally makes for challenging and entertaining games.
What I would like to see is the ability of scenario designers to give objectives and directives to the base AI. This should be doable without undue effort.
For example, I am reworking the Axis & Allies: D-Day game in TripleA. I found that making the game's 3 objective cities German 'capitals', the AI played significantly better.