One of them was the Azure Wish game Hispania, and I just gave it a solo try yesterday.
And of course it made me remember my fond memories of - Great Invasions!
I know that Calvinus is now busy with polishing up World War One, but I do think that actually goes on a very good pace, so maybe it is not too early to start daydreaming about the perfect sequel to GI! Maybe we can come up with some good ideas for Calv.

Altough I think we ought to give the man a bit of rest once he finishes fixing up WW1, he should start to work on GI2 after those 7-8 hours of relaxation!

I think Great Invasions managed to integrate the most historical flavor I have ever seen in a game. It had the historical process of barbarian hordes becoming civilized empires, it had economies, and above all, it was rich in ethnical and religious detail, which I think is crucial for the period in question, since both aspects were wildly fluctuating. And with the strategems, it covered the actions and events normal game mechanics could not incorporate.
Of course, it was far from perfect. Gathering experiences from GI and WW1, here are my preferences for a future GI2:
-turn based! I think the deep strategy genre suffers from real time gaming. It is a strain on resources, and altough EU3 does manage to go by it, I would much, much, much prefer a turnbased game.
-Calv could use the map straight out of WW1, but I would prefer simpler graphics. WW1 has some quite pretty graphics, but also I understand its a strain on lower end systems. The economical, cultural, religious, etc. details of GI must be preserved, even expanded if possible, so resources should be saved.
-the multiple countries thingie. The basic premise MUST STAY. Empires must decay and disappear or the entire historical flavor goes right out of the window, But! Since this was a problem for so many people, how about using the mechanic of that old game, Medieval Lords, or something like that. At one time a player would only control a single country, but it could switch over to an other one, at a cost of victory points. This way, you would get to control a single country, yet you would not be kicked out of the game when your Vandals get overrun by Muslim hordes, for example.
-use the local community. Back in the days, Great Invasions came "out of the blue" for most people. Now we have the AGEOD community, with a lot of people very talented in history, and with a desire to see quality historical games. Best solution could be a payed open beta scheme alá' Stardock.