[R-sig-Debian] Upgrading 2.15.3 to 3.0.x on Debian Squeeze?

[Bill Harris]

I'm running Debian Squeeze on an amd64 machine and currently have R
2.15.3.  Some packages have been installed with aptitude and some with
install.packages().  Now I'd like to update R to 3.0.2 (I upgraded arm
to a version that requires 3.0 :-( ), and I'm a confused.

- http://cran.us.r-project.org/bin/linux/debian/ seems to say I just
  change the sources list to point to '...cran3' instead of to '...cran'
  and then update / upgrade.  Yet
  http://cran.r-project.org/bin/windows/base/rw-FAQ.html#What_0027s-the-best-way-to-upgrade_003f
  (admittedly for Windows) says to uninstall and reinstall R.  Do I
  follow the cran -> cran3 update approach, as I'm on Linux?

- http://cran.us.r-project.org/bin/linux/debian/ says I should run
  "`dpkg -get-selections | grep r-cran` and compare with the list of
  packages supported below."  I've done that, but I don't know what to
  do with that knowledge: do I `aptitude remove` all of those packages
  /not/ listed below or do something else?

- http://www.r-bloggers.com/upgrading-r-and-packages/ suggests a script
  that updates installed packages.  I've used that on minor upgrades on
  XP successfully.  I don't see documentation that suggests it's needed
  for major upgrades or perhaps on Linux.
  http://www.r-bloggers.com/r-3-0-0-is-released-whats-new-and-how-to-upgrade/
  seems to suggest that running `update.packages(checkBuilt=TRUE)` is
  sufficient (except perhaps for what aptitude has to do).  What is the
  right thing to do?

If the answers to those three questions aren't simple, are there
explicit, step-by-step instructions somewhere?  I've looked
unsuccessfully.

Is this a fairly foolproof upgrade?  Minor upgrades have certainly
seemed simple on both Linux and Windows.

Thanks,

Bill

PS: I'll also have to upgrade a Windows installation soon.  I'm running
2.15.3 under XP64 on one machine and under XP on another, and both will
get new installations of W7 after the disks are wiped.  Is there a neat
way to reinstall all the packages I currently have when I reinstall R
(version 3.0.2 on W7)?
-- 
Bill Harris                  
Facilitated Systems
http://makingsense.facilitatedsystems.com/