I have actually been debating switching one of my several rogues to Male undead! In fact one of them used to be male. Back when I had 2k ms constantly I had found that male gave me a slightly slow feel when playing them so I switched to female! however I really do miss seeing male undead rogues with long hair, wsg tabard and agility weaps!
Perhaps it's a result of the bracket I'm in, but there is a HUGE lack of diversity. I am the only active female ud rogue. Our bracket has several hundred female BE characters and I really miss seeing tauren druids (male and female), undead rogues and orcs (male) on horde. In terms of ally I really miss seeing night elf warriors (female) specifically, gnomes and dwarves.
I hope to see a wider array of race/sex/class in the near future! It's becoming very, very boring as of Cataclysm when I first noticed the lack of diversity.