Uhohhotdog of Mathrezim has a leveling problem. In the General Discussion forum he announced that fails whenever he tries to level an Alliance character. He asked if others have this problem. Secksie of Tanaris said that she has the same problem, only she can't seem to manage to roll Horde.
It looks like the issues is not so much faction pride as friends and familiarity. Probably the most important factor is having friends or guildies to play with on the other side. Millaneous of Norgannon said that he doesn't care which side he plays, as long as he's playing with friends. Rummi of Ysera finds difficulty in breaking the link with his main character when playing on