The fourth season begins when Aidan realizes that there is a new vampire coach in town. Josh's new life is shifting due to further problems. There are new powers that Sally takes as she is newly acquired and sends her to a strange place.
The finale touched on a little of everything. It was like a cake made with only the essential ingredients and then topped with icing (the good cream cheese kind, not that overly sugary crap) and served to fans on a fancy dish.
Given the choice between an overly happy -- read: sappy -- ending that gives everyone exactly what they want, I'll take a bit of bittersweet if there's depth and meaning behind the loss, and I think Being Human nailed it there.
This beautifully ridiculous show that at one point literally had Amish vampires wrapped up in cocoons in a barn has turned out to be one of the most emotionally gripping pieces of television I've had the privilege to watch.