There should be a ton of R packages to download here:

http://cran.r-project.org/web/packages

This change is propagating to the mirror websites. For some it might mean downtime with their statistical analysis.

EDIT: Actually, you can still get the packages source code here:

http://cran.r-project.org/src/contrib/

Binaries for mac os x are here:

http://cran.r-project.org/bin/macosx/leopard/contrib/

But I don't know where to get the PDF documentation for the individual packages.

EDIT2: Google keeps cached PDFs, you can view them using Google docs pdf reader.

P.S. I've contacted Uwe, Kurt, and Stefan but probably they are already gone for the day.