I'm fully aware it's NOT in any way revolutionary - I've been using hibernate like feature via Terminal/SmartSleep on macs for years, and it's been inbuilt in Windows seemingly forever - but as it's default it's a whole lot more convienent. Previously, if I was going out all day I'd always leave my mbp plugged in as it'd otherwise drop a couple per cent charge an hour during sleep. I did hibernate the old mbp occassionally but that results in a reasonably significant boot time so I rarely bothered with it.
The MBA, unplugged and unused for 8hrs, dropped 1% and was functioning in less than 3 seconds
The MBA, unplugged and unused for 8hrs, dropped 1% and was functioning in less than 3 seconds