Today, its the Vorthos in me talking.
Wizards is working on each color having their own “iconic” creatures. They have two approaches: tribes and big mythics. For the big ones, dragon for red is the oldest of these, but angels for white and demons for black have been around for a very long time. Lately, blue has been getting sphinxes and apparently, green is going to be getting hydras for a while now (which is fine with Theros coming up, but I don’t like them long term, unless they find new design space for them – which they probably will, my trust in MaRo is very high). For the tribes, red has had goblins since the beginning, green has had the elves, blue has merfolk, even if they sometimes disappear for lack of water, white has humans and black has zombies.
Well, apparently, black used to have zombies. Its not definite, but vampires are moving in. Now, I don’t really mind vampires. They are cool, if done right (note: not like they have been in different media recently, in MtG, they have been generally done right), but to me, they are better if they are kept special.
In Magic 2014, there are two common zombies (Minotaur Abomination and Zombie Minotaur, creatures closely related to each other) and two common vampires (Blood Bairn and Child of Night). All in all, zombies still win (five to four), but previously vampires were only seen here and there.
For me, Vampires shouldn’t be common. They should be rare. Maybe in some sets, such as Innistrad, where vampires are rampant, you can have a bunch of common vampires, but this isn’t supposed to be a poorly thought-out version of World of Darkness. I’d much rather have just Olivia Voldaren and Falkenrath Noble to show how vampires are powerful beings, who can completely take over the game.
Zombies, on the other hand, can very well be common. They have a tendency to proliferate and once the zombie infestation gets going, they are everywhere. At least that’s how zombies are perceived now.
Of course, it is possible that Wizards had a couple of abilities they wanted on the common level for black. These abilities just happened to feel vampiric, so they just put those abilities on vampires. Child of Night has been printed three times before anyway and Blood Bairn isn’t really new ground either, although it is a new card. Black does have access to plenty of things, which definitely aren’t ‘zombie’, so I guess there’s just a need for the vampires from a creative point of view.