Originally Posted by solipsism
I was trying to discern that earlier on iFixit and I haven't read any review that mentions it. The stepping makes me think it can't be any pressing technique I'm aware of and it clearly looks machined. Which is pretty awesome for this type of device.
I assume that this yields three strengthening results over pressing: allows for stress points to be thicker, tighter specs for more accurate sizing, and no weakening of material from pressing process. That is just my speculation, from what you've stated on here over the years you are considerably more familiar with aluminium.
This also implies that Apple has got their machined systems down pat which means we aren't likely to deviate away from them in future Mac notebooks.
What I've also noticed both from the description of how the antenna sits within a machined well under the Apple logo, and the shape of the circuit boards, which also look to fit the machined curves, the unit doesn't need fasteners for some of the assemblies, only what looks to be a rubber based adhesive, which makes it more resistant to shock.
The descriptions of it being extremely rigid, unusual for such a thin device (Remember the Titanium Powerbook?), points to a machined shell. As it's been described as thicker than usually what's seen, that clinches it for me.
Getting that for an inexpensive device (yes, $499 is inexpensive, look at some of the pricing from other manufacturers) bodes well for Apple being able to get the process down in price as Jobs said they would.
Some of the apps and hardware for this are great.
Man, I just can't wait to get mine!