When I bought my first unibody (Early 2009 17"), I was very impressed with the new design (having owned two 17" aluminum and two titanium models). My first impression was that it felt like a solid piece of aluminum when closed. Glad they've stuck with it - continuing and refining the unibody design with the Retina models.
That poor 13" sure took a beating and kept on "ticking" - at least until the corner of a 1400 pound boulder sat on it. (Actually made worse, because the MBP was suspended between two pieces of wood - there wasn't any support from the bottom. I think the display would have been toast in either case, though.)
Thanks for the link!