I thought I'd post a little update on where I'm going with the expansion (meaning that this is stuff I've already done)
- 4 new mages, one for each faction.
- Unique unit for all mages. They replace one of mage's faction's own units. For example Vlad's unique unit is the Vampire Lord that creatively replaces regular Vampires.
- Redone civ trait system. All factions have a base trait and each mage has one of the four additional traits. For example, all life mages are scientific, but each one of them has only one of the four additional traits (commercial, industrial, seafaring and expansionist)
- Some unit graphics have been updated.
- "Space race" graphics have been updated (using rendermad's lighter terrain space race graphics) and a new (simple) video created for victory.
- Monasteries changed to life mage small wonders that produce slowly units with the ability to rush improvements in cities. (gotta see how this goes. I may get rid of the monasteries completely.)
- Dragons changed back to melee units, but they can only be accessed via a wonder that produces them slowly. They are now clearly the strongest units available.
- Unit stats now progress more steeply. Meaning that tech advancement is more important and fighting from a technological disadvantage hurts more.
- Ships carry ~33-50% more units.
- Some small tweaking here and there. (Enchanted springs are cheaper and come more early, Pterodactyls come at early second age,...)
- Some new tech icons (by Lusikka755)
- Some other stuff I'm no doubt forgetting.
Still gotta do
- add some building graphics from Lusikka and see whether I need more
- write pedia-stuff
- test things
- tweak
All in all, the expansion is advancing more quickly than I hoped for - I've basically got the foundations laid out. To my best knowledge, I don't need any more units, leaderheads or other stuff like that. All that remains is to combine it all together, add an additional coat of paint and some touches of chrome.
I know I said that work begins after Christmas, but that was back then. At this rate, I will have a playable beta before Christmas. That wasn't a promise though.
OK, now to sleep. That race of mastery/space race video gave me (and my poor computer) hard time. I should have been done almost two hours ago, but instead I just finished it after restarting numerous times. It's nothing fancy, just a few pics, some fading effects and couple of lines of text, but nevertheless it was a pain in the butt to run through the optimizer.
Good luck on the expansion. Hope it will be as great as the original. 
