It will be interesting to see how much RAM the base configuration of the new Macbook will ship with, because the XPS 13 at $1299 comes with 8 GB.
[1] http://images.apple.com/live/2015-mar-event/images/d02cd9e29...
EDIT: aluminium bends too easily compared to other material. It does not have best structural integrity for its weight. Magnesium alloy, carbon fiber reinforced plastic or titanium composite usually has better parameters for weight.
But I am not saying that polished aluminium is bad or looks bad.
Plastic can flex to absorb the stress without permanently deforming, aluminum not so much. Even the panasonic toughbooks are plastic, and those are probably the most durable laptops I know of by a large margin.
It didn't boot or do much of anything after she had traipsed all over it.
That being said, I am not saying the MB would fare much better, but those Toughbooks are not as tough as they are advertised.
The corner itself was obliterated, leaving a small hole where it used to be, but that was the only damage the laptop sustained.
Unibody metal laptops are nice, but I think the structural advantage of them is heavily oversold. Plastic laptops with metal frames can be amazingly durable.