[jashkenas]

Holy grail, eh? Well, if you really want to swing for the fences...

* Programming a computer in plain English.

* Teaching a machine to compose (real) music, or draw (real) art.

* Simulating a brain -- or, even better, emulating one.

* A programming language that makes it possible to write code that's worthy of being read as literature.

[redthrowaway]

While I agree those are worthy goals, the middle two are CS, not SENG. Real AI is probably the loftiest goal in CS, but it requires a lot more theory work before anyone will be able to implement it.