Yeah I went to get plugs for mine a few weeks back and the parts guy at the local Ford dealership said that they no longer have the "PP" (double-platinum) plugs due to a part # change-over. He said these new ones are the only ones, and they are of course single platinum.
I don't know whether they are as good as the double-platinums because I just got my SHO late last year and never had the old double-platinums in there. My guess is Ford was able to make these new singles to be just as good or maybe better than the doubles. I've driven 1,000 miles on these new ones and they seem completely good to me. Much better than the Champions I had in there for 3 months.