For future reference (at least until it gets buried), the four phases of Fall from Heaven II went as follows:
Light added the magic system
Fire added the Armageddon counter and the Infernal and Mercurian civilisations
Shadow added the Council of Esus and Empyrean religions, the Svartalfar and Sidar civilisations, the World Spells and the Overcouncil/Undercouncil.
Ice will add the scenarios and the Illian civilisation (currently only selectable in custom games)
The team is currently working on ironing out bugs in
Shadow, and the
Ice phase.
Oh and the Age of Ice was the period of time before the game begins. It is a scenario available through Civ4: Beyond the Sword, featuring the Amurite, Doviello and Illian civilisations. It has no relation to the
Ice phase of Fall From Heaven II (besides presence of the Illian civilisation).
Hope that helps clear up any confusion you might have
