This blog is updated daily..
A general description is here.
The internal method of ‘download.file()’ can now handle files larger than 2GB on 32-bit builds which support such files (tested on 32-bit R running on 64-bit Windows).
‘kruskal.test()’ warns on more types of suspicious input.
The ‘as.dendrogram’ method for ‘"hclust"’ objects gets a ‘check’ argument protecting against memory explosion for invalid inputs.
(Windows.) ‘Rscript.exe’ was missing a manifest specifying the modern style for common controls (e.g., the download progress bar).
If a package had extra documentation files but no vignette, the HTML help system produced an empty index page.