Socrates is often quoted as having said "The unreflected life is not worth living". Without becoming too philosophical, I do think this time of year is a great time to reflect on your accomplishments and to begin to consider your goals for the coming year.
What's important, I think, is to examine what you've done well and commit to continue doing those things well. Also, it's important to examine the areas of your work life where you need to improve your skills or knowledge, and bring those up to par. Since we are quoting famous people, it was Einstein, reportedly, who said "The definition of insanity is doing the same things and expecting different results". If you don't examine what you do, and if you don't make changes, you'll simply repeat the same mistakes.
One thing about setting goals for the future - make sure they are RAM. Realistic, achieveable and measurable. For instance, I can establish my yearly goal of losing some weight, or I can establish a goal to lose 10 pounds by March 1. This is a clear goal that is realistic, achieveable and measurable. For some goals it may make sense to identify milestones along the way. If my goal is to build a new building in 2006 which will take eight months, I may want to include some significant milestones along the way - foundation in place by February, framing in place by April, etc.
Too often we set soft goals for ourselves and don't have a way to determine if we've achieved them. Another way to get more emphasis on your goals is to tell other people about them. If you establish a goal to lose 10 pounds for instance, and you tell your co-workers and your spouse or significant other, they can help you in the process. In this regard I keep a list of goals for the year on a yellow sticky pad right next to my monitor, to constantly remind me of what I felt was important entering the year. It's not fancy, but it provides a consistent reminder of what I should be doing and where my focus needs to be.
This year, at the end of the year, take stock of where you are. Slow down for just a little while and determine your strenghts and areas you need to improve. Identify a plan to help you accomplish your goals, and make them as realistic, achieveable and measureable (RAM) as you can. To further your discipline, provide constant reminders for yourself and invite others into your goals so they can provide the encouragement and, possibly, hectoring you'll need to succeed.