What is "new" in Legendary Heroes?

I just bought Fallen Enchantress a month ago when it was on sale on Steam.  I have played it quite a bit before being distracted by a couple other games.  It's god fun, a hybrid of civilization and Heroes of might and magic, which if you have played either of those games last a long time for replay value. 

But seeing as how the new expansion is a stand alone and I can't just get it like DLC (which would be super nice), I was wondering what are all the new things in it.  Maybe just a quick run down all the new features and how it effects gameplay would be nice just to see if the new bells and whistles are worth it.