This blog is updated daily.
A general description is here.
There are new options for more rigorous testing by ‘R CMD check’ selected by environment variables - see the ‘Writing R Extensions’ manual.
‘R CMD check’ now gives a warning rather than a note if it finds inefficiently compressed datasets. With ‘bzip2’ and ‘xz’ compression having been available since R 2.10.0, it only expectionally makes sense to not use them.
