You [can't deactivate][1] Timeline once you've activated it.

> As for Facebook’s help pages, there’s no reference given to turning off Timeline. In fact, the only conversion reference is if you accidentally switch your Timeline to a business page, something which requires contacting Facebook support to rectify.

> […]

> Facebook has confirmed to us that there is no way to return to the old-style profile once you have switched to Timeline.


  [1]: http://www.slashgear.com/beware-facebook-timeline-theres-no-going-back-16202898/