So, I've enjoyed finding stuff on this site, but haven't contributed much myself cos I figure most of the stuff in the game's already been found. But last night I was playing my shaman, water walking and far sighting (aka the lazy man's exploration), and found something possibly interesting. We know Silvermoon (and its accompanying zones) are on the Outland server, but the water around Eversong is covered in invisible walls, and so is the space around Outland itself, so we're not likely to ever cross between the 2. But, I seem to have found that they aren't as far apart as you might think.
While sitting here, facing southwest, and far sighting, I found where the zone ends.
For some reason when I took these screenshots, the sky changed to Eversong, but last night when I was doing this it was still the Ghostlands sky.
So here, you see the back of the Ghostlands, which has a chunk of EPL there for the portal scenery (just like the chunk of EPL in Naxxramas or Acherus). You see the weird stuff that you usually see at the edge of maps; fatigue water turning into land criss-crossing with regular water, dead space and multiplying land. But what happens if I turn the camera around?
For a while it's just more dead space, but if I angle the camera just right, some landmasses start to load in the distance.
I assume it's Netherstorm, as I've heard Silvermoon is located in the Northeast of Outland. Presumably, you could do the same thing with the Draenei island if you knew what direction to face/which corner to look out for. There isn't a whole lot you can do with this info, as the invisible walls prevent you from crossing between, but it's still neat to see where they are.