To me writing tutorials for teaching R these days is same as writing tutorials for Fortran (and I'm sure Fortran still has some nice goodies not available elsewhere). It misdirecting people eager to learn something to a wrong thing. As you can see in this article, every 3rd section of R book or tutorial is often dedicated in gotachas to deal with. We have iPython, Notebook, sci-kitlearn, numpy etc and massive number of R-packages already migrated. I hope there is little need to take trouble of learning R for most people new to it.