I was actually thinking about that the other day, whether we would be able to see other player – in that we would see them in odd places not getting attacked by mobs while we would get overwhelmed by them – though I suppose the invisible thing totaly makes sense.

Yeah, I hit Northrend near the closing days of the WotLK arc, and only really focused on Icecrown and rep while Catacalysm started, so I never really saw anyone (which thinking now, this comic may have just explained) It’s still my favourite zone in the expansion.