This is a fun little tidbit of news, but it appears that someone at Nintendo was very interested in keeping Bowser's portrayal authentic during his cameo in the upcoming Disney film Wreck-It Ralph:

"We did have kind of a check-in process, where we would show them the footage and say, 'What do you think? Is it good?' At one point, (Nintendo) said, 'Bowser's much bigger than that. He's way bigger than Zangief.' We were like, 'Okay, we'll make him bigger. How's that?' They'd say, 'Yes, that's good -- but he wouldn't drink his coffee like that. He wouldn't make that mouth.' (Laughs) Of course, then people from Sega said, 'Well, Doctor Robotnik is bigger.' (Laughs) They wanted their characters bigger and bigger. We were going to end up with these giants in a room, with Ralph as this little guy... But I think that stuff really helped. I looked back on our original animation before the Nintendo notes, and it was like, 'You know, he does look more like Bowser now.'"
-- Director Ralph Moore

Additional information is sprinkled throughout the IGN interview with Moore and producer Clark Spencer.  Go take a look!

Source: IGN: Wreck-It Ralph Creators on Using Actual Video Game Characters