I hear that a lot aden, but have you tried unholy?
IMO people who say blood can aoe as good as unholy, haven't attempted it as unholy. The blood tree simply lacks any improved aoe abilities while unholy has two very strong aoe talents.
This turns your blood runes into death runes after you blood boil, allowing you to death strike twice in a row. More healing power = more mobs.
I am still trying to figure out exactly what all it counts as a disease, but apparently as unholy you can have 4 diseases up on a mob, making your death strikes and blood boils very powerful. (not sure if http://www.wowhead.com/?spell=49032