This is the first year I can remember that divorce rates have not fallen by a hundredth of a percent, but instead remained even. Marriage rates continued falling, by 3 hundredths of a percent in '06 compared with two hundredths in '05. Details here.
The end of summer brings an increase in divorce, or maybe in the initiation of separation, according to this UPI story: Lawyers: Divorce high at summer's end.
However, at least in the version of the story I saw, it is not based on any actual statistics or other objective information; it's just what two lawyers said when the reporter called them. I'm a divorce lawyer, but if there's any such pattern I've been too busy to notice.