My wife is a twin, born on Dec. 30th. We always celebrate Christmas with her entire family on the weekend after Christmas Day. This usually means Christmas, New Year's, birthday all on the same weekend. At least there's a built-in party.
My DS will be one on Dec. 20th. If it weren't for the planned C-sect, he'd possibly be a Christmas baby, too. When he's older, we'll probably do what some good friends do. Throw a party the first week of December before it gets crazy, then a small something to honor the actual day.