I've been seeing this question raised in a lot of the Asperger's groups I belong to on Facebook. Who did you tell when you were first diagnosed? Have you told your supervisor? How do you feel about telling others?
To answer those questions, I didn't hesitate to tell just about everyone I know. As an advocate, I think awareness is imperative. So many of us fall under the radar, and I want people to see that we all don't fit a specific stereotype. I want to show them the many different appearances autism can have. It can be your coworker. Your friend. Your family member. It can present itself in a plethora of ways.
Just as I did with my ADHD diagnosis, I told my supervisor right away as well. I feel that it is important for them to know, especially if you're having struggles. That there is a reason for them, and that you're trying your hardest to work around them. In turn, my supervisor has been helping me to come up with methods to work around my shortcomings, and to hopefully overcome some of them. She has been a godsend!
I felt no reservations on coming forth with my diagnosis. After all, it's just one of many facets that make me who I am. Why hide or be ashamed of it? I want people to see the real me, and I want to be the most genuine person I can be.