While the tire problem is obviously not a consistent one, I can tell you it is not a mere minor inconvenience. Today my car was shaking on the highway for 3 or 4 miles before the flat spots finally "rounded out" on my 3.8. I had reported the problem to my dealer months ago but couldn't do much about it as I was in Florida and the car was purchased in Canada. I'm very anxious to hear what they're going to do now that I'm back.
I got my letter today - I refuse to believe they are replacing four rather pricey tires for a "slight tire noise and vibration" problem as stated in the letter.
My advice - carefully note the tire sizes you presently have for reference purposes before taking your car in for the new replacements.
p.s. there have been some humongous lawsuits in recent years involving tires, but they are invariably settled under secrecy restraints, and are not too publicized.