I'm of the opinion that non-standard evaluation probably isn't the best introduction for converting people from excel to R. As nice as dplyr's syntax is for beginners you can quickly get into the whole ugly side of R.

Also it's often not as simple as just prefixing an underscore, you end up reading the lazyeval vignette and messing about with quote() and formula syntax.

A cool feature of select_ I discovered accidently is that you can pass in a vector of column names to get the corresponding columns, which is much easier than abusing which() to lookup indices.