Yoga - I have this ten minute routine that really helps with my hip flexibility and back flexibility. I broke my hip in March, and I haven't done my ten minute routine since. SO - starting with the new year's, I will return to my habit of my ten minute hip and back flexibility routine 3-4 times per week. It helps with all aspects of my life - from sitting in front of the computer working to doing tasks at the lab bench to racing my bikes to even sleeping more comfortably.
As for weight - I'm pretty much at my winter weight... and new years is always when I start working back towards racing weight... So, I'll be doing that again as well!
Here's hoping for a cancer-free 2013!