For a lot of us, the moment we got the expansion we immediately took our characters to either to Northrend, making the decision to go to either the Borean Tundra or the Howling Fjord first. Quite a number of us decided to abandon our 70's in the meantime to make a Death Knight to be the new main character.
I only got my copy of the expansion a few hours ago so I've had a lot of time to mess around in the Outlands for quite a bit on my characters. I'd usually go herbing to supply my druid's inscription and do some dailies and not much else. Out of boredom from not having the expansion the past few days, I'd just end up logging out early. But in my travels the past few days, I noticed one thing which will end up becoming the trend for quite some time - a ton of Death Knights going around the Outlands! For now, it's the Hellfire Peninsula but I imagine the swarm could follow all the way Netherstorm and Shadowmoon Valley.
Everywhere I went on my druid, I saw a Death Knight whether Alliance or Horde there was at least one. But it's usually swarms! General chat was full of them and the stories are quite funny. A priest in my server who was leveling in Hellfire Peninsula was talking about a 5 man group he was in where there were 4 Death Knights and he was healing. My guild mate who plays a Death Knight was remarking that he didn't notice unless much later in the fight that he was actually fighting an elite because his health never went below 90%.
Another thing I was noticing was the choices on Death Knight races. As I said, I saw tons of them running around Hellfire Peninsula and I was keeping a rough score in my head. For the Alliance in my server, it seems like I only saw Humans and Night Elves and nothing else. I thought Gnome was going to be quite popular? I know that if my DK was Alliance, I'd be Gnome. I noticed that for the Horde in my server, Blood Elves were the most popular but I also saw a lot of Taurens and Undead and slightly less but still plenty Orcs. In my journeys, I only saw one Troll and it was a female.
This brings me to my Death Knight. I decided a long time ago that my Death Knight was going to be either Troll or Orc. I have an Undead Mage, Blood Elf Paladin, Tauren Druid and a Blood Elf Warlock I'm still working on. That left Orc and Troll as the only horde races I didn't have yet. All the guild mates I asked said I should go Troll and i seemed to agree since I liked Berserk and the new Voodoo Shuffle as racials. Seeing that Trolls didn't seem to be a popular choice also made me feel a bit unique or at least give me a sense of cheering the underdog or going against the norm. Of course it might be a while until I seriously get to play my Death Knight if ever i even decide to play it seriously at all.