I really like this mod!
Since there is such a topic here, why not suggest something? :3
What about floating islands? You can also add a couple of new land-based ones.
Some beautiful giant trees (something similar to Genesis or Aberration)
Perhaps custom creatures? (Or do you work exclusively with maps?)
More giant (and not so much) skeletons! Seriously, ancient bones are a great addition!
Too many, right? XD Well, finally I would like to mention some buildings. Lighthouses, castles, ruins (for example, as in Ragnarok or Valguero)

will do. tho im not sure about buildings but custom creatures are definetly coming