As I understand it, it's not on anybody to "use" - it will be the default layout for all user profiles going forward, so everybody will get that for free. Anybody using FB to upload pictures, do checkins, updating their status' and whatever else will automatically benefit from the feature. Doing nothing but enabling the timeline for my profile, the default items on the timeline that they displayed were actually very relevant to events in my life, gave me a sense of nostalgia, and in general made me feel good about what they were doing. It far and away beats the old model of simply scrolling down a person's profile and chronologically seeing any and every story or link they've ever shared. You can still see these less eventful posts with a simple click, but by default their algorithm seems to just pick out more major events to prominently display on the timeline (work changes, if you got engaged or married, photos uploaded of you, etc.).
Still this morning, I start to wonder if the younger generation will start to rely on Facebook for itemizing life events instead of, say, scrapbooking or keeping a diary.