Maybe it's just my game, but there's no werewolf skill tree in my skills menu, even though I am a werewolf and caused quite a bit of slaughter. It doesn't sppear with the mods turned off (but Dawnguard.esm turned ON) either. Do I have to do something in specific to get it to appear?

You can only access the werewolf perk tree when you are in werewolf form. Transform and then check your perks.

As Frank white said,You can only access the perk tree when you are in your beast form.

Ah I see! Makes me hope it's work-around by Beth to add new trees. That means mods could use that little trick also.

Thanks for the answer.