This is NOT good for the consumers at all. Anything that takes away your LEGAL rights is bad for you. Even if most class actions are more money making schemes for lawyers you should still have them as an option mainly because when gross negligence by a company is the cause, no company would ever fix anything they caused without the fear of the class action lawsuits and the bad publicity they generate.
Case and point the XBox 360. MS did not give your that extended warranty because they were being nice and thought they need to correct those poorly soldered motherboards. They did it because people were going to bring class action lawsuits against them and they decided it would be cheaper to just extend the warranty and try to get some good will. If the XBox 720 or whatever they call it has the same issues, I think you will hear a lot of complaining on the net, but no action from MS to fix it, since no bad publicity will be generated by a large number of buyers bringing on a class action against them.