As for not going with a straight chronological list, I think that really the idea behind Timeline is to take all the information that was put in Facebook and present it in something that is more akin to digital scrapbooking. They want you to have something more personal and emotional so that you're more attached to it. Their ad about it is clear about that: Facebook should be the place where you keep track of your life and expose it (a certain way) to and share it with your friends.

For that, you want to highlight a specific picture or event, but still have little anecdotes sprinkled here and there. They want you to go through the Timeline like you'd go through a photo album where you'd have a mix of the big events (graduation, marriage, births, etc.) with the little things, so that you can hear "oh, remember that one? When we went to Disneyland and you fell in the pool…", "you were so mad at him that day! Look at what you wrote on your wall…", etc.

Not having just a list makes it a bit more interesting to peruse. It's like going through a shoebox of photos and souvenirs, spread them out and you see some things, not others… I'm not saying they've nailed it, but it's a first version of it and it's an interesting experiment. It's hard to make an interesting photo album by hand, it's even harder to make something semi-automated.

As as side-note: The new timeline is why I quit FaceBook in December.

I find that interesting since I personally rarely see people's profiles or timelines.