Cyc is a dead end. The project has gone on since 1984 and very little useful has resulted from it.
At best we have network scanning tool (that's not as good as a trained sysadmin watching the same traffic), a search engine query tool (that consistently returns less relavent results than Google) and the so called 'Knowledge Server', which has yet to show its worth.
The problem is that the they're trying to model an analog, nondeterministic process (thought, common-sense, drawing inferences based on loosely/nonrelated facts) on a digital, deterministic system. Computers are incapable, at the most basic level, of things like lateral thinking, hunches, etc.
Computers are only capable of discrete, pure values: 0 and 1. How do you model the subtle gradations of 'maybe'? You can't do it without a perfect computer with infinite registers. Common sense is about as likely as artificial intelligence: it won't happen on transistorised hardware.