First off, I'd like to say that after Derek follows through with his promise to remove the bunny slippers as a random drop and make them sovereign-selection only, I WILL BUY THE LOOT DLC. In the future, please make the gag items optional.
Second, here are some ideas for DLC that I would purchase in a heartbeat:
1) More Mounts - I love Bonesplitter and if you made a mounts DLC, i.e. panthers, black fire horses, pegasi (plural pegasus?), lizards, rhinos, whatever, I'd buy it. As long as they weren't ridiculous. Seriously, though, this is a must.
2) Spells, spells, and more spells! More spells for each of the elements and make then tactical AND strategic and I WILL BUY IT.
3) A new faction or two.
4) More technologies. leading to more items/units/buildings/WONDERS
5) Hell, more wonders in general.
6) More random events. More Badlands. MORE MONSTERS!
7) All of the above.
Seriously, I'd buy each of these if you made them. Keep the tone in line with the tone you've already set. I understand easter eggs, but I don't want cutesy shit in my Elemental world. If you can provide any or all of these in your DLC's, or just make another expansion with all of these, I'd be one happy customer.
I am already, but I'd be even happier 
