I must be a lucky bastard considering all the whining here. Spent almost 7 hours in STV last night going through most of the quests and I was outnumbered and killed only once. I ran into a lot of Horde players but most of the time we left each other in peace. Not sure if it's because people have a hard time killing Hunters in general and that's why I don't get attacked as much but I don't feel it's hard to level up questing as an Alliance player. When I do get attacked it's mostly by 2 or more players but it's not very often.
Perhaps you should stop pissing Horde players off by killing them on sight and they might not come back in bigger numbers to fuck you up.
Oh yeah, Ashenvale is an exception. Holy shit they ganged up on me in Ashenvale, that place is a war zone.