There's been debate over whether or not people with Aspergers have higher IQs or are generally smarter than the average population. I'm not going to debate that too much, nor am I going to debate what exactly "being smart" means (knowledge vs. intelligence, etc.). I will say that most Aspies often have an abundance of talent in one or two specific areas. Sometimes, the area that benefits is brain power.
I fancy myself a pretty smart guy. School was a breeze for me, I'm really good at my job and know a lot about it, and I sometimes scare my wife with how many answers I get right on Jeopardy. I've wondered: am I smart because of my Aspergers, or in spite of?
As always, I have a theory.
People with Aspergers don't have a strong sensory filter; it can sometimes be impossible for an Aspie to block out stimuli. Because of this, the Aspie brain is forced to process incoming information at much higher speeds simply to avoid a sensory meltdown (parents of Aspies know that sometimes the incoming stimuli is so overwhelming, these meltdowns can be absolutely unavoidable). It's this adaptation that gives Aspies the ability to process knowledge faster than a neurotypical brain can. They catch on faster. It's easier to "get" it.
Whether or not this ability is used to the fullest advantage differs on a case by case basis - not every Aspie is guaranteed to be a genius. It takes hard work to realize this potential.
I also think Aspies are primed for intellectual greatness because people with Aspergers tend to focus their attention on hard facts. The greatest thing in the world to an Aspie is a question with a definite correct answer. Actually, the greatest thing is knowing the correct answer. Subjects with "gray area" responses - such as social situations and debates - can either be annoying or downright scary to an Aspie. Incoming information from these subjects can often be conflicting and contradictory - there is often no "right" answer. Aspies are are more comfortable with asbolute answers than relative ones.
So don't always think that just because a person with Aspergers seems smarter than you, that means he is. He may know the "right" answers, but he doesn't have all the answers.