I would like to see Poland as a selectable civilization in Civ4, at least in expansion pack.
Why?
First of all, culture. There are few hundreds millions ppl living in Eastern Europe, but authors of Civ4 had noticed russian culture only

. I want to say that Poland was Russia's greatest rival in this area for centuries, and significant cultural alternative, as russians preferred despotism while poles personal freedom. Nicolai Copernicus, Maria Curie-Sklodowska, Walensa and Solidarity movement, John Paul the Second - they are all polish contribution to world's culture. Josef Bem played a vital role in the Spring of Nations (ca. 1848 liberational wars throughout Austria, Germany and Russia), while Americans should remember Pulaskis and Kosciuszkos as well.
Second, history. We were always important part of Europe, from the very beggining till today, and in XV-XVII century, in union with Lithuania one of the greatests powers (biggest country with the largest population, nearly 25% of the whole european population lived in Polish-Lithuanian Commonwealth

). Battle of Grunwald was one of the biggest battles in medieval times, and the Battle of Vienna was one of the most important battles in european history. Northern Wars (Fights for Dominium Mare Balticii), between Poland, Russia, Sweden and Prussia were an event which forged the future shape of whole Europe.
To people diminishing Polands importance - please, if you want to talk about european history, look wider and catch the whole context, not only the peak of your nose. Don't be so self-focused.

.
Third, balance. Try to play Europa Universalis, Medieval Totalwar, Knights of Honour and see, how the presence of Poland changes strategical situation, goals and alliances.
Four, the number of civs for the different culture groups:
West Europe:
France, England, Germany, Spain, Vikings, Celts
East Europe:
Russia

mad
Mediterranean:
Romans, Greeks, Carthaginians
Mideast:
Arabs, Persians, Ottomans
Far East:
Chinese, Japanese, Mongols, Koreans
South Asia:
Indian
Africa:
Egyptian, Malinese, Zulu
North America:
US, Aztecs
South America:
Inca
Please tell me, which group has smallest representation and explain - why

?
Of course, I would see as well a new civ for South Asia region (Khmers?), and at least Iroquis civ for America, maybe Ethiopian (I find them better then Zulu) for Africa, but for me Poland is next in the queue.