My main problem with it is that, at least on most pages I've seen, the left and right columns don't sync up chronologically. On my band's page, for instance, our posts about new stuff always go in the left column, but a post our singer made about our first demo a year ago just stays at the top of the right hand column, forever directing people to out of date information.
And the fact that it's billed as a "timeline" -- and yet on the top right there's just these boxes for apps and "recent activity." Completely ignoring the "timeline" idea.
Further, people posting on my wall doesn't really make sense to be be part of my
timeline. That's for convos back and forth, not really life events. Meh.