I found a wild Werewolf today near Riften, my character has a real low armor rating so I had to run away. Also had another first today, a certain random encounter that happens at night.
Companions are the only way to contract the beast blood. Other than Aela being able to re-infect you, and the various wild were-wolves there are nothing else added to werewolves. And on a personal note I believe the werewolf perk tree is rather lacking in comparison to the VL tree, all wolves are now are just as fragile glass cannons.
I wanted to max out the werewolf tree today after maxing out the VL tree, but when I transformed back it gave me a human body on my Khajiit. Kind of ruined it for me, I'm gonna hold off a bit for now for the werewolves.
I'm loving the new werewolf tree, I've taken the 3 of the damage, the health, and double health on feeding and I haven't died once as a werewolf. (I died a few times before I got the second damage, but that was fighting the silver hand though)
VERY viable. If anything, its too overpowered! I destoryed all of Whiterun hold and killed 3 dragons without dying once, within one hour. Much prefer it to VL too... Havent found any wild Wolves yet though... but they're there