A helpful study[1] found out a lot about an Autism Service Dogs and parents, and these results can give you a good idea of what to expect (even if it's not an Autism Service Dog, but another kind of Service Dog that you're getting).

While we recommend that, for the first six months "all good things come from the handler," in the long run, often a Service Dog isn't just for the handler—the Service Dog often also serves as a calm and obedient family dog, helping the entire family deal with stress. Families experience a lot of stress when caretaking for a child with special needs, and this responsibility is a significant hardship on them. Thus:

• Parents and siblings need comfort and an outlet for their stress.
• Having a loving Service Dog in the family helps because the dog can lend a sympathetic ear to the family (when they want to talk to the dog), and the dog can be there for each member of the family to cuddle, play, and exercise with.
• Even if the family decides that the dog should only interact with the handler (and not the rest of the family) for the long-term, caregivers are comforted to know that they have a tool available at all times to help with their charge.

The study found other benefits to parents in having a Service Dog in the family, including:

• Parents or caregiver can bring the Service Dog to the doctor's office with the child, and know that the dog will be a good tool to help relax both everyone.
• Caregivers feel more relaxed at night because the dog is with the child.
• Caregivers feel more in control and calmer in general because the child had a Service Dog.
• With parents of children with autism, the parents consistently say that although the dogs couldn't be specifically trained to prevent the child from wandering, many dogs figured out on their own how to prevent the children from bolting and running away.

We realize that having any dog in the house is increased work (picking up poop, feeding the dog, etc.), but the goal is that the work in taking care of a dog is more than balanced by the benefits, not only in helping with the handler, but also in helping the entire family deal with stress. 

[1] Burrows, K. E., Adams, C. L., & Millman, S. T. (2008a). "Factors Affecting Behavior and Welfare of Service Dogs for Children with Autism Spectrum Disorder". Journal of Applied Animal Welfare Science, 11, 42-62.