Excellent Anime. Includes zombies. Watch it.
WARNING: it is not complete yet
Season 1 is 12 episodes. Then there is an OVA.
Season 2 was supposed to be released sometime this year (2011), but apparently no one has any clue if that is true due to the OVA.
Once again, if anyone is following this stuff LET ME KNOW WHEN THE NEXT SEASON COMES OUT. (as with Nyan Koi!)