A valuable enhancement to R would be to add the ability for a user to provide feedback easily. The R main menu Help menu could have a "Feedback" item that the user could fill out and submit. Also, each individual help page within the ? help system of R could have a "Feedback" link to allow users to submit feedback on that particular function or item.
I realize this might create a deluge of feedback that could not be handled. If you could figure out how to sort the wheat from the chaff, adding a Feedback item would be a great addition!