Serena's achievements post turning 30 are amazing; 3 consecutive US Open titles, 1 Wimbledon title, 1 RG title, 3 consecutive YEC titles, an Olympic gold medal in singles, back to back Miami titles, 25 WTA titles in total, back to back year end no. 1 finishes (including holding the world no. 1 ranking wall to wall this year), and I think she is now mathematically certain to reach over 100 weeks as world no. 1 just as a 31-33 year old.
Winning the Australian Open is the only significant feat that she hasn't accomplished in her 30s. It has been nice to see her treating the regular tour events with a lot more importance after coming back from her pulmonary embolism scare, in sharp contrast with her attitude towards them until 2010. Still I would expect her to cut down the number of smaller events that she enters next year, so that she has more in the tank for the slams. She is 33 years old after all and she needs to schedule carefully.