If re-release rough rider not in original form then we can always get a body replica from Kamtec and put it on a news 2wd (or even 4wd) buggy. Why wait for tamiya?
One important point: the Rough rider series was interesting also because of it's long history and availability of option parts from so many companies. Nowadays, seldom do you see 3rd party make a differential from scratch for any cars.....