I won't bore you talking a lot about the mountain top fishing spot that gives access to Hyjal fish because its already been discussed in multiple threads. Obviously I claim no responsibility for finding that spot.
However, every method to gain access to there seems to require hacks or crazy exploits to fly up there. Another thread found a different spot but you don't get the Cata fish very often and it seemingly still required hacks.
I found a fairly simple way to access the good fishing area without using any hacks or means of flying dead or alive, the only thing you need is Levitate (priest 2m castable buff).
You can go fish on your Priest and do this solo or bring one with you, you will need almost the full duration of the 2m buff. Obviously this could be annoying for some but you don't need to hack to get there and I hope some will appreciate that. I made a quick video below, I apologize if it takes long to view on slow connections I wanted the quality a littler higher to make it easier to see what was going on.
Basic overview is this, start at the spot you are teleported to for reference, ride to the cliff pointed out in the video, use the priest levitate as a wall walk and face in-toward to the mountain while moving slightly to the left until you reach your destination, its really easy.
Re-uploaded video, blizzard petitioned the deletion of the first video on Vimeo, trying Youtube.
Double click the video to goto youtube if you want to watch it in 720p, you can't expand the video pane on the forums here.