R has to be good enough to go up against expensive tools such as SAS and SPSS.

"And what has to happen is the open source tool has to be good enough, right? This is what happened with Linux. Linux was a toy until, all of the sudden, it was good enough to run financial services houses that didn't want to pay the premium for Solaris anymore. And we're right at that inflection point with R where it's just finally gotten good enough that it can go up against some of these well established, expensive tools."

 

http://radar.oreilly.com/2009/07/making-government-transparent.html