I apologize ahead of time for this post being mostly critical of other people's ideas.
I love Marcus, so I hate to say that his vision of an Insect faction is diametrically opposed to mine. I think that with bugs, perhaps more than any other faction, you could justify having every unit be a customized specialist for its purpose. I don't necessarily think Insects are a good/ideal candidate for the design goal of "good vs attack power 6", but they could be if you designed them that way. But I would save Insects for a different design concept, like "anything goes". Maybe there should be 12-15 types of insects, as a design concept(?).
I love Brook, but I do not like the idea of Deep Dwarves, or Gnomes, or whatever. I'm just not excited by a reminds-me-of-dwarves faction. I think it is a flaw in the product line that three of the ten fantasy factions are Elves of various flavors. I'm less opposed to numerous human factions, because lets face it, most fantasy worlds seem to be based on the premise of "humans of various flavors are numerous, compared to the non-human races, and that is why they tend to dominate the landscape."
I'm half Chinese, so I say with a twinge of guilt that I'm not excited by the idea of the Terracotta army. I want to be; maybe if I saw the cards?
I'm also half Viking (believe it or not), so I say with absolutely no bias that I still like my idea of tough fantasy Norsemen. I don't know if it's the best idea for the faction concept that the community can come up with, but I still like it.
The Ogre army has some appeal to me. It fits the concept very well, and it's different enough to not remind me of other factions. Yes, the M&M pack has ogres, but those are mercenary ogres who wandered away from their homeland! Maybe the M&M ogres were the ones who couldn't get wives back home, so they have to wander the world, looking to kidnap Amazon women in their chainmail bikinis...
Beastmen? I like the faction idea, but it's probably not a great fit for the toughness 3 concept.
If I had to vote today:
1) Something we haven't thought of yet
2) Vikings/Norsemen
3) Ogres
-DC