Add this line to your script to tell F# interactive how to print out the values of R objects:
fsi.AddPrinter FSIPrinters.rValue
RProvider discovers the packages installed in your R installation and makes them available as packages under the RProvider root namespace. The actual package is lazily loaded the first time you access it.
Currently you need to load up a real R session, then install the package via install.packages, or the Packages/Install Packages... menu. You will then need to restart Visual Studio because the set of installed packages is cached inside the RProvider.
The most likely cause is that RProvider is using a different R installation from the one you updated. When you install R, you get the option to update the registry key HKEY_LOCAL_MACHINE\SOFTWARE\R-core to point to the version you are installing. This is what RProvider uses. If you are running in a 32-bit process, RProvider uses HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R\InstallPath to determine the path. For 64-bit, it reads HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R64\InstallPath. When you install a package in a given version of R, it should be available in both the 32-bit and 64-bit versions.
There are a couple of mismatches between allowed identifiers between R and F#:
It is pretty common in R to use a dot character in a name, because the character has no special meaning. We remap dots to underscore, and underscore to a double-underscore. So for example, data.frame() becomes R.data_frame().
Some package and function names are reserved words in F#. For these, you will need to quote them using double-backquotes. Typically, the IDE will do this for you. A good example is the base package, which will require an open statement where "base" is double-back-quoted.