Nintendo actually came up with a lot of new ideas, they are still one of the innovators in the game industry. However, they keep using their OLD characters their NEW ideas, for example: DONKEY KONG Jungle Beat, MARIO kart, ZELDA four swords adventure, DONKEY KONGa, LUIGI's mansion, paper MARIO, WARIOware. You don't see these game ideas before they were released, like Mario Kart on SNES I believe was the first kart racing style game.

They could easily replace those characters with some new ones, then that would be a totally new franchise in people's eyes. But they didn't. They rather used their old ones - which makes people think all games Mario are something from the past, even when Mario Party or Mario Pinball first released. I understand why they keep using those old characters, I mean, why use some unknown characters when you have some popular ones in your hand? They make a lot of money by making "MARIO" golf than some "new character" golf. However, while they are making money now, their characters are getting old. They really need to make some new characters to refresh a bit. New idea will still look old to people when you keep on using old characters. They need to plan for the future before everyone is sick of their characters.

A lot of companies that seems to have a lot of new franchise are actually using the same game idea, take just one of many examples, remember those extremely sports games that were very popular couple years ago? Most of them play the same with similar mechanic. However, by getting a different spokeperson for your game like Tony Hawk, Dave Mirra, or just come up with a new name like Aggressive Inline, and you know what? All of them are NEW, different and valuable franchise back in the days in people's mind.