Android :: What's Learning Curve For Phone?

What has people's experience been in learning Android? I'd be interested in how long it takes to get to the point where you're writing your first app, and how the experience compares to learning some other programming API. I know several professional programmers who have tried to learn Android and failed. Is it inherently more difficult or larger than you might expect? But there's a survey here http://www.infoq.com/news/2010/07/Mobile-Survey that claims Android has the shortest learning curve of all smartphone platforms. I wonder how the survey guys could have got such a perverse and unlikely result. I have my own views and observations on this, which I'll mention as a dialog develops. I don't want to bias the discussion with my perspective at this point.