Your first race/class.

Counting early friends and family, Night Elf Rogue. Later on in beta, a Human Paladin, an Undead Warlock, an Undead Rogue and an Undead Priest.

First ever!?

Well, technically it was an Orc ... warrior I think. That's only because it was the only race/class in the game at the time. Early testing would rotate through races so we could get focused internal testing on them and their leveling. I believe we did the same for the Burning Crusade beta, only allowing Blood Elf or Draenei at specific times. Hrm, although that may have only been in a pre-public beta form now that I think about it, I'm not sure.

First character in retail was a human paladin.

I'm not entirely sure on the first Beta character, I played everything at one point or another but I think it was an Orc Warlock.... Orc Shaman in retail. No, I don't see a pattern here.