I have no idea how popular the servo library is. I wrote my own simple stuff using the 16 bit timer a while ago. Maybe it's one of those things which "isn't useful until it exists"?
My interest is stimulated by low-cost robot arms. I have one, but it is so low-cost it isn't servo's but just DC motors, so I will have to build all of the position encoding and feedback myself. We thought something more sinuous would look more intriguing.
I'll have a look
GB-)