Just read this:
http://www.thekeyboard.org.uk/computers%20become%20self%20aware.htm
And was a good read, especially about the bit in 2029 when its predicted computers will become as complex as the human brain!
But have a read and tell me what you think. Have you seen any evidence which suggests they will become self aware other than what ive said?
I personally think they can only ever be self aware when they can think for themselves and execute (even build) programes themselves which were not pre programed. But as that article said proving it will be tough.