For those of you were were in the various Debian infrastructure channels, you might have noticed that I was playing around with wanna-build, dak, sbuild, and buildd and friends. [Thanks to everyone who answered questions, btw.] Over the past week, I've been building most of CRAN, Bioconductor, and omegahat for unstable, amd64. I plan to build the same set of packages for i386, and will start a build shortly for stable as well. This effort builds on top of Charles Blundell and Dirk Eddelbuettel's cran2deb, which does most of the heavy lifting.
If you're like me, and use lots of different R packages, or already use some of the R packages available on the previous build, you can simply point your sources.list to the [http://debian-r.debian.net] archive, load the appropriate GPG key, and away you go. I have a bit more information available here and I will try to keep that page updated as I build other architectures and build out for stable.