Personally, I don't really know what to think. I don't see the privacy issues with the Timeline, because it's not like it automatically finds out all the information about you, it just presents the info already on the site in a different way. If you don't want someone seeing something, don't put it on the Internet at all. Even if you set your privacy settings some way, it could be found out later by a change like this.
I don't really care if people can scroll through my facebook life, because they're only going to see content for about 3-4 years of my life before it just says dates and the day I was born.