Chalid said:
The clue here is that the Clan of Embers is not a orc civ but more or less the unification of Nonhumen races, orcs, ogres, goblins, lizardmen, whatever Pseudohuman we find.
So there is nothing that speaks against an extra Race of Lizardmen that are Seperate from the Clans of Ember. We might try to flesh out the other civs some more before we think about adding additional ones i thin.
About the Undead. I do not like the undead to be a seperate Civ. Therer has to be a leading mind behind them and undeadth is covered nicely by the death sphere.
I would like it much more if undead was a way your mages treat your People... For example right now you can get three additional Archmages when you turn your first three archmages into Liches. This concept seems intersting for other units as well.
Maybe we could add additional Death mana only units (Necromancer) that would require death mana to be built (diplomatic penalty!) and allow to turn other units into undeads as well. So you could turn your Axemen into Undead Axmen and so forth. The Advantage could be that undead units would not cost any financial support, but they would all have the undead promotion and be easy targest for destroy unded spells and undead slaying units. Maybe they would have otehr advantages/disadvantages as well.
Ive been intentionally keeping out as this discussion, just seeing where it goes and reading with interest. In the end I agree with everything Chalid said above.
Specifically:
1. Just as Chalid said the Clan of Embers is a grouping of non-human "monster" races. In FfH lore they all have a common ancestery but are more prone to mutation (seeing a much wider range of divergence between generations) and therefor adaption into the various environments and forms.
2. The point above is the "lore stuff" and Im perfectly willing to toss it out if it makes the mod better. We are not attempting to recreate my D&D game, we are trying to make the best Civ4 mod we can. There are no sacred cows. I include the point above just to give a little reasoning for why they were put together.
3. I dont have much desire for new civs right now. Mostly because I feel like we have so much work left to do on the existing civs. Until they are complete I doubt we will see more. In game terms this means that "Light" is probably closed to civ additions, but I would be willing to consider them in later phases. (Woodelf this is a task you, you will be there when we put together a build list for the next versions, bring this up).
4. Specifically for the lizardmen, I dont see a functional need. What is it that makes them different? The water travel is neat, but I think it will be spoiled if it is used to frequently. In fact I think we are in danger of robbing the Lanun of their designed sea mastery if we bring in a race that is better at it than they are. It seems like we are designing from the flavor (we like the idea of lizardmen so we are trying to design a civ around them, instead of having a design need to fill). I must admit, the lizardmen models that C.Roland made do look awfully cool and beg to be used as something more than what they are.
5. The best place I would see lizardmen being used would be in the "Shadow" phase as one of the Wilderness inhabitants. As a jungle or island dweller.
As for the undead civ, again I agree completly with Chalid. I like the idea of a unit that requires Death magic to create, a Necromancer sounds perfect. But we may want to consider a different mechanic than passing the undead promotion to the units, which seems to be a little close to the vampire mechanic. I thought about a necromancer before but i havent been able to think of a satifactory mechanic for him.
I like the idea of an undead army but I dont know what would functionally describe it, what are its penalty's and strengths? In fact that question is a big one for me right now with all of the races. I want to add effects to the various racial promotions, we just need to figure out what they are.
cost with a -1 str penalty? I always think of the undead as swarming.
....No time to play, neither to try to write something about Lizardmen,....just enough to read what's new 
