If anyone from Firaxis is still browsing the boards, I have a couple of suggestions for the Multiplayer Expansion.
1. A centalized Firaxis server showing all TCP/IP games in progress. Free host servers would also be a bonus.
2. A ranking sytem compiled from the end-results of these games -
http://ngworldstats.com/ could be used for this.
3. For PBEM/Hotseat games:
It should be easy enough to implement a replay of all visible activity (especially combat) by other players/the AI at the start of a player's turn (as opposed to getting a pop-up box summary)
If anyone else has any more suggestions - post 'em here !