I remember Coertas being one of the most expansive and beautiful areas in the game, and I can't remember the particular area but I remember there being some trees and level 99 Goblins (I believe it was on the Eastern side) which was my favourite.
On another note, there was an area in 1.0 which had 'walkable' land in the Ashpool, called the Dreaming dragon. I never figured out how to get there, but for it to be named it seems a shame that it was seemingly inaccessible. Would be nice to finally go there, unless of course they're not opening up the Twinpools area, and only the Riversmeet areas.
Worth noting is that Dragon's Aerie was in this area - one of the many unfinished and unreleased dungeons from 1.0.
I think Wyrmking's Perch will be back, since, well, everything's been pretty 'dragon-y' of late. Along with that we should see the Dusk Vigil. Weather or not we'll see that as a dungeon as well, I have no idea. And wouldn't it still be encased in ice a la snowcloak?