As I am sure you are aware, the majority of my posts are in Stata. My primary motivation for choosing to post in Stata has been that this is the program which the majority of the professors I work for have been using (Jeffrey Wooldridge, Andrew Dillon, etc.). However, I have been and continue to be a reluctant user of Stata. Frankly, I do not see a reason to buy a program that costs upwards of $800 (often more) in order to do work that could be done just as well on a program which is free.
So far I have been content to use Stata because I am more fluent with it than R. However, now Stata has released a new version (version 12) and I am stuck back in version 11 unwilling to pay 595 to upgrade my version. So unless someone decides to upgrade my version for me, very likely, then most of my future posts are going to be in R. Hope you find them useful!