It's thin, light, stylish and does it all. The SSD inside really makes the product blaze through tasks - and allows it to start up in 8 seconds! The i5 processor is more than enough to handle video playback, web browsing and the such, while the updated Intel HD4000 graphics make it a pretty decent gaming machine for it's size - running Portal 2 at over 60fps on all high settings. (with 8GB RAM the Shared VRAM goes up to 512MB) OSX Mountain Lion is simply a bliss for ex-Vista users - it simply works, with no lag when launching multiple apps - and a whole suite full of incredibly useful apps built in. The Battery life of the machine is also outstanding, lasting up to 8 hours with just basic web browsing; it's hard to believe they fit a battery in such a thin, sleek aluminium enclosure! The Keyboard and trackpad combo is simply astounding - with the wedge shape design of the computer aiding comfortable typing. The Gestures on the trackpad are also so smooth on the glass surface, almost feeling natural after a while.
As for things that aren't so prim and proper - I find the lack of ports slightly disturbing - while I have no problem with the lack of a DVD drive (sacrificed for portability) it's quite annoying how they haven't included an ethernet port in the space of the currently useless thunderbolt port. (though adapters are available for the thunderbolt port) It's also quite an expensive machine, but it's probably worth it considering how long it will last! The one final issue which I can see coming up is the lack of space - while the SSD is certainly faster and smaller, it does sacrifice a lot of space - with 256GB certainly not enough for most people - though I guess an external hard drive can fix that.. (I am not paying £500 for a 512GB upgrade)