R 3.4.0 was released some days ago. A compatibility update to RStudio is also available.
The repositories at this site and obviously also at CRAN now contain package binary distributions for R 3.4.x and R 3.3.x.
One major change in this release is that the JIT (just in time) compiler is enabled by default. I have not done any benchmarking yet.
I have written a page explaining how to upgrade your R installation.
The code examples in my book Learn R …as you learnt your mother tongue continue to work as expected. However not all the package updates for R 3.4.0 are yet in CRAN. In package ‘gganimate’ function gg_animate() has been renamed gganimate().
The code examples in our book R for Photobiology: Theory and recipes for common calculations run without problems. Due to recent updates to the packages in my R for Photobiology Suite, used in the book examples, fewer warnings than earlier are triggered.