<shrug>
Returning to thread topic, I do hope that there'll be another expansion with more civs being added. Poland is the most glaring omission -- has there ever been a Poland in any Civ series?
Nope.
@Mark Jenkins: I prefer Austria over the HRE for several reasons. First, the Austrian Habsburg royal family had the greatest number of HRE Emperors, and largely dominated that body for centuries. Austria was one of the largest European empires back during its days before the rise of Prussia/Germany...it controlled half of Italy, the land that would be Belgium, most of Southern Germany through the HRE, and Spain, at one point. Not to mention they played a pivotal role in European history by fighting the Muslim Ottomans (and being saved at Vienna). It's true that it was important in the Early Modern period, but its importance dates back even further. It's ironic you mention the Thirty Years War: who were the Holy Roman Emperors during that time? The Austrian Habsburgs. Not to mention Charles V played a very important role in the Reformation, and was a Holy Roman Emperor (and Habsburg) not more than a century before.
The Charlemagne scenario could have still existed without them adding a specific leaderhead for him--I would have preferred consistency in the leaderheads, and using all Medieval-looking pictures like they have for everbody but Charlemagne, Saladin, and Justinian would have been nice.
I don't make my votes based on World Maps, because I don't particularly care for the World Map. So, just throwing in another African Civ or Polynesia to make the World map prettier doesn't really cut it for me. Poland, I think, has always been the honorable mention, and if they add a few more in Civ5, Poland stands a chance of being in the final expansion pack, assuming they follow the Vanilla + 2 Expansion Pack formula they have used before.
I don't think there will be another expansion for Civ4, but I could be wrong. BtS seems awfully...final to me. I'll side with ewu.7walker for Benin, if you want another African civ. But for me, Austria and Hittites are top picks.