I hope I am wrong but I KNOW I am not: I don't believe at all that online or even LAN multiplayer in this game will work at all. It will be hard to keep players committed to a game like this when they start losing. TBS tend to last a long time and having the losing side waiting to make just a couple of moves while the winning side plays its long rich and satisfying turn just never works in my experience (I have played games like this for 30 years, starting with cardboard wargames). The loser surrenders and leaves VERY soon.
The only way I have ever managed to get this kind of games going was PBEM (Play By E Mail). I have played huge maps of "Age of Wonders" and "Age of Woneders Shadow Magic" for months, one turn each day. A player plays his turn then sends it to the other player who sends it to the next...
The way we made it work was as follows:
I would usually make a map then start playing. After about a couple of weeks of rounds I start another game with the same people so that we have two going at the same time, then another couple of week and I start a third one. Three is the good number usually.
That way after about 2 months of playing certain players start realizing that they are weaker then the others, but keep playing all games for several reasons:
1 They have other two games going where they hope they will be able to win.
2 The game where they are starting to lose begins to be boring for them, but since their empire is smal (they are losing) playing their turn and sending it is not that time consuming.
Before they realize that they are condemned and I am also going to win the next game the first game is over and a fourth has started. I can tell out of personal experience and years of testing (!!!) that SUCH SYSTEM WORKS. On the other end if we were playing at the same time, the losing side would have to wait an hour for me to end my turn, when they just have a couple of units left. NOBODY WOULD EVER DO THAT! And it would be embarrassing to me to enjoy myself while my friends are clearly bored.
This is a very important piece of info for the developers, please don't underestimate this I have tested this for years!
Age Of Wonders Shadow Magic still survives thanks to PBEM, their forum is crowded even after 7 years!
(I know what you are going to say PBEM had a drawback: battles against other players can only be solved in autofight. True but the player can fight all battles against teh AI, thus developing his empire that way, before the confrontation. To be honest once you start playing, you don't really mind: since the autofight system in AOW is extremely well done.) - Besides THAT IS THE ONLY WAY MULTIPLAYER WILL EVER WORK!