If you met most people I know with Asperger's, you probably wouldn't know they had Asperger's. With or without Asperger's, everyone has a unique way of behaving in new social situations and behaviors associated with Asperger's might not even be apparent until you got to know someone well.
Mary McDonnell is fine actor. She's brilliant as the president in "Battlestar Galactica," but in "Grey's Anatomy" her character's behaviors were overdone, exaggerated and just plain inaccurate.
A reviewer from The Star-Ledger in NJ agrees with my assessment: "Maybe we start with the usually sublime Mary McDonnell doing her best Rain Man impression as the heart surgeon with Asperger's. I'll admit to some personal sensitivity on this issue as I have a lot of personal experience with people in my life who are on one point or another of the autistic spectrum, but all of McDonnell's scenes were played so broadly (and with the hateful cutesie-pooh, "You're supposed to laugh now!" music underscoring them) that my eyes rolled so far into the back of my head that I can't actually see the computer monitor right now. (Thank goodness for that touch-typing class I took in 10th grade.) It was like watching an episode of "Boston Legal," where even the characters who don't have Asperger's act like they do to suit David E. Kelley's bizarre comic sensibilities. And for her diagnosis to come as a complete surprise to Bailey? Really? I want to hold out some hope for the later episodes of this arc, but this was an awful start."
And on Amy's how many lives blog , you can see a clip of Mary McDonnell talking about the role and read Amy's fears about the direction the show is going with the character.
I think ABC is approaching a crisis point with what they are doing with "Grey's Anatomy." First, a homophobic decision to dump the fine actor Brooke Smith because the show decided for no reason (I guess some network exec's homophobia is the reason) to axe the development of an interesting lesbian couple, and second, introducing the ghost of Denny to the show. I think "Grey's Anatomy" has officially "jumped the shark."