Throne of Kil'jaden you can't reach without a flying mount. Trust me, I tried to climb hills with my warlock. It doesn't work anymore.

I managed to get to Teldrassil on my Shaman pre-WLK when she was just five levels above the guards. I didn't die or get ganked once. Try doing it early in the day and ride quickly through the purple portal and hug one of the "walls" to the left or right as you curve around to the Teldrassil exit. Don't go straight through, it's suicide.