They aren't loyal fans though, after they finish the main quest they just trade in oblivion at gamestop for call of duty. Probably majority of the people that bought oblivion were past elder scrolls fans and the thirteen year olds added to the massive sales. In the end its probably the TES fans that give majority purchase, aLso Fallout 3 is not The Elder Scrolls so you can't compare the target audiences.
ah but you can because like i said, they probably know nothing of the series.
im sure somewhere theyll see "from the makers of fallout 3 and oblivion"...
dont even get me started on oblivion
as for the rating i agree with those saying the rating shouldnt be the issue
make a great game, take whatever rating ESRB finds appropriate