Courtesy of CRANberries, there is also a diffstat report for the most recent release As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.
Changes in RcppArmadillo version 0.4.200.0 (2014-04-07)
Upgraded to Armadillo release Version 4.200 (Flintlock Swoop)
faster transpose of sparse matrices
more efficient handling of aliasing during matrix multiplication
faster inverse of matrices marked as diagonal