Yes 12" Macbook thinner than the current MacBook Air.
If you sit on it you'll bend it badly.
http://www.theverge.com/2015/3/9/8175329/new-macbook-specs-features-release-date-price
The Macbook Air display, crack easily if you do not have a hard shell cover...even with that, a slightly heavy bump will produce a waterline in the display, I speak from experience. I do not own one, but gave one out as a birthday present, what I had said occurred, I had to talk to APPLE Customer service for a free replacement, the service centre here in Singapore, wanted around $1,000 plus to replace the screen, which has a waterline display at the bottom right hand edge. Anyway, they replaced that for free after authorisation from APPLE. This was only 2 months old then, the user had not dropped the unit, but could not remember ever bumped it either, there was no bump on the body nor crack on the screen.
My own Mac Book Pro Retina Display, which was brand new, 1 year back, suddenly displayed a off & on flicker line on the left hand side vertically, the flicker line changes colour, I brought the unit to Service Centre & they wanted $$$ to change the LCD. Called APPLE & got it replaced for free...& found out later, that this was one of the inherent defect from those Retina Display; had this occurred like now, out of warranty...the price to replace $1,000 plus, btw, it is good to buy the APPLE CARE extended warranty for 3 years!!!!...
Now with the new Apple Book 12" Retina Display, APPLE going have a field day, making $$ out of cracked screen & tons of money from selling adaptors...you need adaptors for the new port, even a external Superdrive you need an adaptor plus the new power adaptor is new...
That's the way APPLE make money out of us....:p