There should be no exceptions for illegal aliens regardless of their skills,or economic status. Illegal is just what it says, illegal. How could one distinguish a highly skilled individual from an almost highly skilled individual? What determines highly skilled? If an illegal wants a job with NASA what does he have to do to get it? Be a citizen with no criminal background I would say. So, if the law was broken how would he get the position? With homeland security as it is a criminal background goes a long way.
If they are so highly skilled as to require positions that we consider substantial such as : NASA, academia, government, CEOs of business or even entrepreneurs, then they probably wouldn't be illegals anyway. The vast majority of illegals we have seen are mostly migran workers or general laborers. Given this fact they are very intelligent. Illegal immigrants can and do learn quickly how to do a job and they give it there best in order to gt the cash!
Most people who we consider highly skilled would have in place a way of going somewhere and doing it legal. If not I am sure they would petition the government and go the right way in order to gain citizenship. We must always remember though that in 2001 there were some highly skilled people here in the United States that went to school and learned to fly passenger jets. I know that no matter how hard we try we can not protect ourselves from everyone but we can make it a little tougher for them.