It is a new R IDE, F14 rpms are not available
The external F13 rpm does not work on F14
Also it is not in Fedora package database.
Compiling from source (on git only) is not an option for many potential users.
http://www.rstudio.org
I have added it to
https://fedoraproject.org/wiki/Package_maintainers_wishlist#Q-S
Best
A. Mani