Completely hooked on this show. My sister asked me over Christmas if I'd seen it yet; when I said no, she went out, bought the first season DVDs, and we watched them all in one day. Following season 2 now on PBS, and even though I know a couple of spoilers already (boo!), it hasn't lessened my enjoyment of it. Hope they air the Christmas special over here sometime as well.
I also read yesterday where they are set to start production on the third season, and that Shirley MacLaine has been cast to play Lady Grantham's mother.