I noticed this when I bought mine. The dealer I purchased the car from may have just been blowing smoke, but the service manager said it was caused by a weatherizer that was sprayed on them to protect them during cold storage coming in contact with high temps and sun. Regardless, I got the haze off no problem when I got the car home (1000 miles later).

1.) I used Meguiars Diamond cut compound (it is a pressure sensitive cut compound for buffing paint and clearcoat) and used it on my orbital to break down the thick, crusty stuff. You should not need to apply that much pressure, and there is no need to mask anything since the product will not damage the paint. BE CAREFUL not to let the edge of the orbital grind against the painted surfaces too long or you could burn them. For me this wasn't much of a problem because most of the haze was on the upper part of the lens.

2.) I used Mothers plastic polish to hand buff the lenses completely clear. Hand buffing allows you to get all the way to the lower corners.

3.) Liquid Glass polish over them; which is the polish I use on the whole vehicle, paint, glass, and all.

The whole process took about 20-30 minutes.

I never shot a good pic of how bad my lenses were, but they were pretty bad. Here is a photo of the car before (best I had) and a close up after: