I hadn't seen this method posted anywhere, so I decided to make a video of my escape of Black Temple.
This is a no skill required explore. Also on a side note, you can go the other way instead of going the way I did. it will yield the same result.
World of Warcraft - Breaking out of Black Temple 4.3 - YouTube
UPDATE:
I just wanted to update. You can bypass multiple bosses and if I'm right, you should be able to bypass all the bosses up to Mother. I'm not quite good enough at mountain climbing, but I'm sure it's possible.
As far as getting through that invisible wall, it's just like any other one.
Working
- Blink
- Darkmoon Tiger/Passenger Mount
- Mushroom chair
- Charge abilities
- Shadowstep abilties
What doesn't work
- Heroic Leap
- Fear
- Walking up to the wall and /dancing