To be fair though, Nissan originally had 17,000 pre-orders but had trouble filling them due to production issues. It remains to be seen if Tesla can actually deliver their first run, but let's hope that Tesla is able to get some magic done in that NUMMI plant.
Models like the Honda Hybrid Accord and Civic didn't do nearly as well because aside from the badge and carpool sticker, they didn't scream "I'M A HYBRID LOOK AT ME SAVING THE WORLD"
My hunch is that the Leaf was an attempt to capture some of that "conspicuous hybridization" momentum. Agreed, though, it's an ugly car.
I find the Prius OK, not beautiful, but not ugly either. Don't have one yet, but would likely consider one as a practical replacement vehicle.
I recall hearing somewhere that Nissan did for aerodynamic reasons to make sure the slipstream goes over the side-view mirrors, but boy does it look ugly. As an engineer, I usually never find myself arguing in favor of aesthetics over effectiveness, but in this case even I think they should have done something different.
That said, I'm not a car designer, so there might be other factors going on there.
I've driven one a few times. It's ugly, but not more ugly than a lot of other econo-cars like the Fuse. I'm tall and it's fairly comfortable inside, and it performs fine.
If I was still a daily driving commuter and still had two cars in the household, I'd definitely be interested in the Leaf because it would save me $250 in gas a month and let me drive in the carpool lane.