Yes Nintendo has done a great job. Like a Beauty Queen, if Mario ever had to step down for unforeseen reasons, I could see anyone from Link to Samus to Kirby to a bunch of others step up and take the roll, and do it better than most.
Funny story: When I had a 7800 growing up, I actually thought Pac-Man was the Atari mascot, since he was so well known and at the time, he wasn't on the NES or Master System. (I didn't know about the Intellivision version until much later)