1) Deepest Guk----has been announced
2) Rujarkian Hills (Sol C?)-----Hinted at in the next patch. Also, there are is the goblin graphic on the start-up screen. Just found a link too http://www.gamespy.com/interviews/july03/ldon2/
3) Everfrost----Just a guess. They'll want a winter theme, and Everfrost has some good memories for many people

4) Befallen/Mistmoore/Unrest----They'll want an undead type dungeon and any of these will fit the bill. I tend to lean towads Mistmoore.
5) I kinda ran out of ideas here. I'm stuck with Runny Eye or possibly a CT spin off.
Anyone else have any ideas or predictions?
Btw, 48 zones is rather impressive indeed. I especially appreciate this response from the above link:
These zones (and there are more than 40 in this expansion) are anywhere from one half to three fourths the size of an average EverQuest zone. The physical space for this expansion is as big (or bigger) than any we've made to date. And none of that space is empty open grassland, it's all dungeons -- all content. In terms of content, I think this is the most ambitious expansion we've come up with to date. That extra effort will be obvious to the players once they experience LDoN.