I think some people miss the point of the Turing test. The point is not to determine how intelligent someone or something is, but to determine how good a computer is at imitating a human.

It is kind of a joke to imply that a human fails the Turing test. On the surface, it says they're stupid. Literally, it means that for some reason, someone mistook them for a computer. Reasons for this are varied. for example, they could have just been acting incredibly stupid. (It's not hard to do that, you know.) But also, adherence to strict rules, exceedingly lengthy answers produced rapidly (good knowlege coupled with high typing speed), refusal to answer (or demonstrate understanding of) off topic questions, ability to solve math problems very quickly...all of these could cause a human to fail a Turing test. Actual documented Turing tests have included humans that failed for all of these reasons; essentially, because they were too smart or too rigid.

Over all, the test does not test how human a human is, but how human they act during the test. Except as a joke, It's fairly meaningless to say a human fails the Turing test. Humans are included in the test as a control in the experiment.

As for computers passing the Turing test...this is now a reality, and happens quite often these days. You just have to lower your standards as to what you expect of a human. Unfortunately, these expectations don't seem very high for some reason in chat systems like IRC. A sufficiently large expert system that is able to produce meaningful replies can pass the Turing test fairly easily. In IRC, it probably wouldn't take more than a few months to build such a system to pass when evaluated by casual observers. Around 1993, I remember witnessing a 3 year old 12M expert system in IRC pass the Turing test so well that we were unable to convince some people that it wasn't human.

To pass the Turing test, it doesn't have to be intelligent. It doesn't have to be powerful. It just has to be able to imitate a human, even to the point of imitating human flaws (such as slowness and stupidity). Alan Turing's original intent for the computer Turing test was to determine when the computer's reactions were sufficently complex as to fool a human.