Notwithstading the programming/scripting language, there are some other "minor" issues like the absence of religions from CivV.
So no point in porting FFH2, better work on FFH3.
My guess is that we will get, at first, a barebone Civ for "suckers". Then, in due time, all the cool features like religions, corporations etc will crop up in successive expansions.
So why bother starting working in six months on FFH3 when the needed mechanics are two and half year away, at least?
I think that for the moment it would be better develop FFH2's modmods, while trying to define together, as a community, what we would mod in FFH3 in an year or two. Units, unit lines, resources, civs, balancing issues, religions, etc. Implementation should wait until CivV has the two or three "expansions" required by today's marketing standards (*).
(*) CivIV had two expansions. EU3 three. StarcraftII bridges the difference between expansion and franchising. Duke Nukem 4ever will rewrite the very meaning of the word expansion. And yes, Duke Nukem 4ever is a turn based strategy game, too. You just switch to a 1st person shooter for every single unit combat action, and to a real time tactical game for mass battles. Whenever you build a city, a city simulator will pop up for you to decide the street layout and the zoning of residential and workshop areas. Anytime you finish a city building, the simulator will query you for its position. Whenever you build a wonder, you switch to a wonder building simulator where wonder pieces fall from above, which you need to rotate and translate into their right positions. Of course, spying missions will be first person infiltrations in the urban environments you and the AI developed, and the sims you meet will be generated by buildings, civics, religion present etc. Be wary when exploring cemeteries late on friday nights and never move close to carps during golden ages.