To begin with, I'm a Pythonista for much of the time. Even so, I can see how you will probably land in the world of R; here is why:
- * R comes with reasonable facilities for statistical processing and, on top of that, has important extensions that allow for remarkable features. Example: Setup R language, with snowfall->snow->Rmpi extensions. The result of this would be *fault-tolerant* *scalable* code, within relatively simple codebase. It cannot be overemphasized how much functionality you get out of the box in such setup, with basically zero code changes (in R).
- * Python is great when it comes to integration with other languages/codebases. It could well be the best scripting language since... the invention of bread. As another poster mentioned, it can also interface with R via Rpy, so it's not at all a black-or-white decision.
In short, both are first-class tools for scientific computing and you should compare and choose them on technical merits basis.