As we all know, planescape torment was one of the best rpg's ever made. However it never got the attention it deserved and thus it didn't sell as well as for example Baldurs gate 2. The reason why is because of the setting; a dark and twisted world in some kind of parallel universe.
Most gamers were used to be in some kind of fantasy land with Elfs, Dwarves , orcs etc... so this was quite a big change for the average rpg player, so they usualy didn't want to play it right away (maybe after hearing some really good comments from people who have).
Divinity had the usual Fantasy setting but RR has the Planescape one (barren wastelands and no pretty grassy fields (which is too bad because I loved the Divinity nature atmosphere)).
I know RR will be a great game just like Divinity and I will get it as soon as I can (just like with DD <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />) but i'm afraid that people who haven't played DD won't be too attracted to this title.