zpiloto - I was just looking at your post again and you've had those wires in for 30,000 miles? It doesn't seem like the wires have degraded in the slightest (though I don't know what they started at).
Like I mentioned before, I've wondered if wires actually need to be replaced as often as a lot of people say (I've heard many say every year or every other tune-up). Seems like a rather large expense for a few less ohms of resistance when the vehicle can actually run fine with high-resistance wires.
From Bosch's site:
Any time a wire exhibits physical damage either to the wire or the boots, such as a cut, grooves or marks from chafing or scorch marks from burning, the wire should be replaced as preventative maintenance.
Additionally, some wires fail from the inside, due to a breakdown of their insulation materials. Wires should always be inspected and tested whenever a rough or erratic idle is present, poor acceleration is noticed, a decrease in fuel mileage is experienced or a vehicle fails an emissions test due to high hydrocarbon emissions or cylinder misfire fault code.
Wires should be replaced if their resistance exceeds the OEM specifications for their specific application. Wires should always be replaced as a set due to the unpredictability of the internal condition of each individual wire.