There's a not-entirely-positive view on Ken Rolston's influence in this interview with Douglas Goodall
http://www.uesp.net/wiki/General:Douglas_Goodall_Interview
Interestingly thats the one that caused a hissy fit and is edited, he stated in the original interview that Todd likes going into dungeons with an axe, and that Douglas liked prying secrets from old tomes, a lot of that content was removed. Which I don't understand, Oblivion shows Todd's preference in spades, why try and hide it?
Thanks Lady Evenstar that was the interview I wanted to link too
Both these interviews do show the change in TES quite well