Although I really hate the new timeline crap, I see why they are doing it. They make all these changes because they don't want people to become bored of facebook. They need to change it up every once in a while to keep people interested, or so they think.
Anyways, it was originally going to be forced onto everyone starting December 21st, but the date keeps getting pushed back. My guess is they are having a lot of problems with it, or are getting to much negative feedback.