Here is how anyone at any level can access the entire world, free
1. Download speedhack
2. Download mountain climber
3. Go to StormWind Inn
4. Get into Warsong BloodGulch, not 3 (capture the flag PVP game)
5. Keep playing and use speedhack to get all 3 capture the flags
6. Eventually, you will taken to the Nightelf island, at the top left corner of the world (forgot the name of it now :confused: )
7. Activate mountain climber
8. Clock speedhack at 11800, get out of there, go east
9. Once you are at the big drop out of the island, clock speedhack at 10000 and walk down or slowfall if you are a mage.
10. Swim to Kalimdor or anywhere you want to
This was done on my lvl 17 mage, I got to lvl 18 by EXP from discovering new places. My map is almost completely full for eastern kingdom, about 50% full for western kingdom.
BY THE WAY: Watch out for high level hordes. Explore with speedhack set at a minimum of 12500. 11800 or lower allows interaction with NPC's still.