I'm a noob but I'll jump in anyways.
I can't speak to the playstyle yet, but from a content theme standpoint here are a couple of things that would interest me:
- Arabic style army - could bring in units such as flying carpets, dervishes, camel mounted cavalry, etc.
- Asian style army - tons of possibilities there, already discussed.
- Ogres - thought of them before i saw the art posted in the general forum, honest!
- Swamp creatures - could be terrain focused, big slimy critter units (battle slug!), frog riders, insect swarms, could be lots of fun. Actually the more I think about this the more I like this race!
- elementals - different ways to go here, could be armies of individual elemental groups (earth, fire, water, air) or it could be mage controlled with units from each element. could get some interesting army building as well (fire and water units can't be within x inches of each other, etc)
- Celtic/Norse/Barbarian - Yes, I know they're all different, but I lumped them together anyways. They could be used for historical battles later, or they could be used for fantasy and incorporate their mythology in. Valkyrie units! The Morrigan! Bards!
- Clockworks - love the idea and had thought of it before reading the posts here! Honest!
- Minotaurs - Nothing says battle like a bunch of minotaurs charging across the field snorting with big axes!
- Chaos Army - actually that's one army that doesn't do much for me. It's been done. Actually, I guess most things have been done. But this one, eh. I'd rather see elementals.
- Halflings - somebody had to say it. Not sure how you could go about making them different from humans, elves, etc. but the possibility is there. Maybe they could have a pie thrower elite unit.
- Arachnids - Creepy spider people. Don't even want to think about them.
Well those were just some thoughts I had and wanted to share.