Conrad Sanderson just released the second pre-release 2.3.92 of what will be Armadillo 2.4.*. This is now in RcppArmadillo release 0.2.31 which is already on CRAN as of this morning.
The NEWS entries summarising the changes for both are below:
Courtesy of CRANberries, there is also a diffstat reports for 0.2.31 relative to 0.2.30 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.0.2.31 2011-11-28 o Upgraded to Armadillo test release 2.3.92 "Loco Lounge Lizard (Beta 2)" * fixes for linking on Ubuntu and Debian systems * fixes for inconsistencies in interactions between matrices and cubes