C++11 with R and Rcpp: supported by CRAN policies?

This blog entry by Dirk Edelbuettel states:

Rcpp, as a CRAN package, follows CRAN policy in not (yet at least) supporting this standard [C++11] for its purported non-portable status.

The blog entry is two years old, and I've been wondering if this is still true (both with regard to the CRAN policies, where I did not find any hint about C++11, and Rcpp support).

Moreover, I would like to know what this means exactly. I used a CXX_STD = CXX11 statement in the src/MAKEVARS file (rather than Sys.setenv("PKG_CXXFLAGS"="-std=c++11") as proposed in the blog entry). This seems to work with the C++11 features I am using (mainly the tgamma function), Rcpp, and R. But will I get ripleyed when I submit my package to CRAN? Will the package not be available for some operating systems?