Can we replace Human Brains?

Last year i went to a Hysea conference and in one of the talks there was a mention of how there will not be any testing groups in two years or five years from now on. It was an interesting topic, atleast in the lecture or on the papers.

My mind did not agree to that statement at that time and I thought that might be because of the fact that I love manual testing. Even now, after one year, it's still the same. One year or ten years, I think products can't survive without manual testing. Can we really replace Human brain? Lets take an example... we need to test a login screen with valid user name and password. Can we say that there is no problem if we try with all valid inputs? There can still be hundreds of problems there. You can be extra smart and automate every possible case there and build a super computer to run all your billion tests. Can we still say that there will not be any other problem? Login might work but it might be taking 10 seconds instead of one second or the screen might be flickering a lot while logging in. How many of these can we automate? How many every tests you build, I still think that human brain can not be replaced. There is lot of judgement involved while testing. We question a lot of things. A smart brain can even narrow down future problems while testing. Machines just say Pass or Fail, good brains tries to see if there are other problems irrespective of Pass or Fail.How can we replace a brain with a tool or a machine?