Hadley Wikham's work has made the R environment much more tolerable and interesting. Because of it, R can be a pleasure to work with.
I would be far more excited about the possibilities created by a cornucopia of new stats/dataviz functionality built into Python than I would be about some packages that make R a bit less terrible to write.
- JavaScript
- PHP
- C++
- ...
On that note, Hadley, R IS awesome and a large reason for that is your contribution to it! Thanks and keep up the good work!