I think the author is conflating two issues - (1) learning Rails and (2) keeping up with the latest developments in Rails. I agree with the author that (2) is

I think the author is conflating two issues - (1) learning Rails and (2) keeping up with the latest developments in Rails. I agree with the author that (2) is getting harder - but this is the price you pay for improvement. I disagree that (1) is getting to be overly difficult. By and large, the changes to Rails 3 and Rails 3.1 make it easier for developers to do more advanced things with Rails. If you just look at the simple tutorial applications that newcomers to Rails are starting out with, I don't think their complexity has increased very much from Rails 2 to 3 to 3.1. Yes, they are different from version to version, but this doesn't matter to the newcomer. TL;DR - the framework has more functionality, which makes it more difficult to learn the entire framework, but it is not significantly more difficult to learn how to accomplish any given task.