Where do you get your information from? R can take advantage of multicore and grid environments through a wide range of options. The multicore SMP package is one example, Rmpi and snow another, while gputools makes use of Nvidia cuda processing.
The data limitations is architecture specific (32 bit), and R x64 has no such limitations. In fact, packages exist in the R community to efficiently and quickly handle large datasets (see for instance ff and bigmemory).
The HighPerformanceComputing task view lists the many packages available to parallel processing and large data handling.
Revolution Analytics has taken the work of the open source community, repackaged it and resold it with support as value added. This is fine under GPL, but PLEASE do not claim that they have made some enhancements which did not exist in R. This is blatantly false and I would be very sorry if such lies are propagated by Revolution. The least you can do is check you story before publishing.