won't happen any time soon, but it will happen someday.
For all the reasons given so far of course, but also because computers are not compact enough or advanced enough (or both, which is what's needed). To do the job properly you would need something approaching Turing-compliant systems which can make intelligent decisions rather than just today's mindless automation.
Then you would need years of experience and testing before they were able to be put into practical use on heavy jets.
Finally, would you trust your life to anything with a Microsoft label on is....?
