In keeping with my recent battlegrounding streak to complete my arena season one collection, an e-mail sent in by Rihlsul caught my eye this morning. He writes that he has noticed a recent increase in the volume of AFK'd players who "park their netherdrakes and kodos as on-top-of-BG-masters as humanly possible."
Now, other games often get around this by giving each character and NPC its own space, mutually exclusive from the space around it. In other words, you can bump into things, but not stand in them, enveloping them. While such a method may be more true to life, I think WoW's way of doing things is quite handy, considering the sheer numbers of players in big cities or on heavily populated realms.
Unfortunately, it can indeed become a bit of a nuisance. I become especially frustrated in the banks, when some characters feel the need to stand in the banker, rather than in the crowd, or when I find it difficult to click target a quest-giver.