Just to clear a couple of points for you Sparkplug. The "Holy See" isn't the Pope alone, it's the general rule making organisation - a bit like the Governing Body!
And Williamson wasn't excommunicated for holocaust denial. It was because he was part of a breakaway group of ultra-traditionalist priests led by Archbishop Lefebvre (?sp). This is the group that the RC church were trying to make peace with by reinstating the excommunicated Bishops. That Williamson is accused of holocaust denial is a 'side issue' (a very big one!).
I'm not too sure whether it was a good idea to reinstate him. It would probably have been sufficient for the Pope to reinstate the others for now.
On a side note, i'm taking this oportunity to remember the forgotten/ignored 5 million non-Jews who also lost their lives.