idk if this is new but i remember when it was super easy to get up there and then they patched it.... but that wont keep us off it for long! This is tested and does work, just matters if u do it right.
1.First go to the normal spot outside orgrimmar where you would jump to get over to the section that leads up the mountain.
2.Now, your at that section but u cant go up... Just wall jump back and forth till u get up the first part, past where you normally cant go.
3.Next just normally walk as far as you can over to the left, you should b standing on solid ground now and dont have to worry about falling if my instructions have been clear enough so far.
4.Now, if you are as far as you can go to the left, you should see the end of the mountains going down, and the river dividing the barrens and durotar, careful not to fall!
5.Turn to the right, you should see a mountain going up and the side of it curve around where u came from, and behind you a hole, dont fall in its annoying but u CAN get out.
6.Back to the mountain, curving around from where you came from in the beginning, carefully wall jump up and across the curve, jumping back and forth till you get near the top, you may have to go across a few more times till its safe to go up.
7.Now your on top of the Orgrimmar mountains and not the actual city, find a outcropping of rock to the right, near the orgrimmar gate, the old one might work but I used one that is a little higher up and farther out.
8.Just jump and pray you land in the city.
9.Now you r about in the same place you would end up in the old days before the patch, enjoy exploring the upper parts of the city!