ME WANT!
Longer timeline: Ab Vrbe Condita (since the foundation of Rome) until... how about until the "official" fall of the Western Roman Empire? For a total of roughly 1000 years. With several topical different starting points, of course.
Areas: More Asia (Persia, India, western Russia, Baltic area, maybe China?), whole Europe (including Iceland), more Africa (Ethiopia, Somalia, West Africa, Azores), maybe Greenland?
Populations/nations: all the populations involved in those areas and timelines, including those in the Italian peninsula (which may end up destroying Rome before it has a chance to expand!), and those that might form from splintering the Roman Empire. Spontaneous appearance of nations in previously gray/non-civilized provinces, corresponding to the historical events. Same for "core" provinces of dominated cultures.
Events: ditto, everything included in that period... notably 0 AD, rise of Christianity, Mithrans, religious convertions, pax romana, civil wars (competition for the throne), important nomad barbaric raids (3rd century), etc...
Other: easier and more interactive characters and governments system. More military techs (especially naval), deeper colonization, option to build (and name) new cities, more detailed politics (Vic2 style), a better religion system (give a "patron" deity to every new state leader, with different bonuses, for example)...
Now I have to say goodbye, folks... back to editing my Communist Roma, Fascist Roma, Monarchic(al?) Roma, Republican Roma and standard Roma flags.