Ok, finally found out how to do this via a friends guide:
Hopefully this is a little more specific. (with pictures!)
Head to Darkwhisper Gorge in Winterspring and the 'room' with the raid portal to winterspring, your cursor will be on the 'Da' of darkwhisper gorge on your map.. find this pillar... it in the north eastern corner of the 'room' near a cave entrance...
Now, stand aganist the pillar, and use the jump-then move forward trick, bounce around for all you are worth... eventually you will either get onto the pillar proper, or end up wedged between the wall and the pillar like this...
from there its only another jump-then move forward onto the pillar. This
technique gets easier with practice, believe me it works tho. Make your way round the pillar...
and use the jump-forward to get here.....
and mount run forward mounted (this can be tricky, you may fall down and have to start again) and jump to here..
and dismount. Jump past the tree, should be easy by now.. and head left (west) up onto the stone platforms..
from there, head right up the soil ground onto the second rockplatform..
and to get off this platform, stand roughly in the middle..
and use your jump-forward, and your up... leaving you to see the other side of the entrance...
if you fall forward here, you hit an invisible wall, as shown in the picture...
dont worry if you do, this wall can be your friend, as it is VERY easy to
jump-foward along it. If you head right along the wall it shouldnt take you long to reach this spot...
from there, jump down to the right, around the invisible wall, and your into Hyjal
Remember: If someone reports you, or a GM sees you in Hyjal, you will be banned. You have been warned.