Brads mentioned Ideologies and poaching from Civ games, which would seem to suggest that ideologies are akin to Freedom/Autocracy/Order. But he also seemed to indicate that ideologies replaces the Good<---->Evil axis. Right now it sounds to me like ideologies will be social engineering options with diplomatic effects (as in Civ 5), but a different set. I am however, hoping that the ends in view will be a lot more varied.
The highest good, the ideological endpoint, might be personal, such as honor, religion, duty and/or transcendance; it might be a goal, such as acheiving the technological singularity, purifying the galaxy of [evil | organic life |other intelligent species], uniting the galaxy diplomatically, converting the galaxy to Bokonon, cornering the galactic market on left-handed windchangers, &c. Or, hell, it might be discordian: keep everyone else too distracted and disunited to resist your insidious manipulations, so that whoever seems to win is still just another puppet of yours.
Since all these will be, IIRC, in XML files, we will presumably be able to add new Ideologies such as tridecaphilia (a fascination with the number 13), which gives, for example, a big morale boost every 13 turns? This of course would require the ability to set triggers, etc.
One disadvantage of GvE is that it means the other side automatically hates you. With ideologies, some goals can coexist. Since races need not be equal, neither do ideologies. The ideology "Organic Life Must Be Erased" might be a weak ideology relative to "Death Before Dishonor" because of a strong penalty (no trade routes) coupled with a weak economic benefit (more revenue from piracy). I myself would be tempted to select a weaker ideology if doing so removed some micromanagement (no longer need to protect my own trade routes, since I have none). Fun trumps balance. And balance is difficult when races are truly different.
TL;DR - Unique races good. Balance? pfui!