So, out of sheer boredom and motivation to visit the places that used to be so easy to get to long ago, I came up with an idea, then tried it on live. Rogues, specced Subtlety for Shadowstep.
Now, most people will either: A) say this is a repost; or B) say the idea does not work.
Both are incorrect. (I checked before hand to see if the post was done before or not, and found it was not.) Both myself and a friend attempted it, and managed to get into Old Ironforge using a combination of walljumps (To reach the area to duel near the throne room) as well as the shadowstep glitch to jump through the wall. It actually works, though my idiocity did not think to take pictures of the venture.
So we got the idea to try it on multiple areas, and it so far has worked on Old Ironforge (as mentioned), Hyjal, and under Stormwind using the backway from Loch Modan (through much hard work, and the use of a noggenfogger with the Glyph of Safe Fall). The idea is, the shadowstep puts your out of the parameters of the game, allowing you to simply "walk" through the invisible walls by teleporting behind your buddy that stands withe his/her back against it. It is an effective way of getting to the once easy hidden locations of Azeroth.
Any other suggestions or critiques on how these 'feats' can be achieved?(I have been on this site for a very long time, and just have not had the time nor thought to post anything. Please be a bit 'kind-hearted' with your critisizm, if you would.)