I'm not sure I'd describe them as healthy, exactly. They do place a strong emphasis on using good ingedients, but portion sizes are huge -- a chicken burrito is more than 1,000 calories.
Chipotle's meats (particularly the steak) can be quite bad at times, but the rest of their stuff is pretty good, and their chips are great. I haven't been to a Taco Bell since a Chipotle opened up in my neighborhood, despite the Taco Bell being quite a bit cheaper and only two blocks further away.
But maybe if they get everyone to try it _once_ as I did, that will define success?