This blog is updated daily..
A general description is here.
list.files() (also known as dir()) has a new argument
'include.dirs' to control whether directories are included in
the listing: the default of include.dirs = !recursive is
unchanged.
Package 'tools' has new functions checkRdaFiles() and resaveRdaFiles() to report on the format of .rda/.RData data files, and to re-save them in a different compressed format, including choosing the most compact format available.
A new INSTALL option, --resave-data, makes use of this.
New function Sys.readlink() for information about symbolic links, including if a file is a symbolic link.
Printing a list could segfault if the elements are nested too deeply.
cat() on an unopened connection could close it twice, and file() connections segfaulted on some systems..