User blog comment:DJ MC CJ/Focusing on Season 16 and Season 17/@comment-99.46.82.154-20121119165238

(Taken from the official Facebook Page) it looks like this is the "special" announcement...

Arthur:

I'm excited to announce that my one-hour special, "Arthur's Perfect Christmas," will be airing on PBS KIDS this holiday season (check your local listings). You'll have multiple chances to watch, including a special primetime broadcast on Sunday, December 16th!