Originally, the Leaf's battery meter was more accurate. Zero really meant zero.
One of the first problems reported by new Leaf owners was that they would run out of power while on the road, because they were expecting the meter to work like a typical gas meter, where zero means "fumes", with a few miles to spare.
There was a firmware upgrade, I believe in May 2011, that changed the meter so that zero means about 10 miles. Also Nissan recommends that you only charge to 80% capacity, for increased battery life.
I have never let my Leaf get as empty as zero bars, although sometimes it gets as low as one bar.
A more precise meter would be nice. I'd like to see a one-percent resolution. But I'm happy with it lying a bit about the capacity, because I don't want to be stranded, and I don't want to discharge too deeply. Since I drive over 60 highway miles daily, I do give it 100% charge, which isn't the best. When I get a charger at work (perhaps one of the converted cables mentioned in the article) I'll be able to drop the charge to 80% and extend the battery life.