That's like criticizing the comic book industry for using the same character for 60 year and not using anything new when in reality they had introduced many characters throughout the comic that have to do with that character.
Others have done it GoW,Gears of War,Halo,etc. Tons of people do it.
The Nintendo characters just have to much potential because they don't try to be realistic.
They can make their characters out of yarn or paper if they want to, now could the other companies get away with that?
Or maybe the fact that the most of the games you say they rehash are actually one entire story line have anything to do with it.
As for zelda they are trying to do damage control.
And most Mario games have no timeline even the paper mario games.
Though being able to adapt a character to nearly anything given means you may as well not make another one. Though if you can tell me the time that Sony and Microsoft produced a game that had 10 yr old boy fighting something that can destroy universes you call me over on character development.
Personally Nintendo needs to retcon Zelda and start over and pokemon as well the games they have can be much better if they follow this.
Though I don't know what you are talking about with characters when the things they mostly release at Sony and Microsoft are super soldiers and the fact that Sony and Mirosoft just buy company's and have them make the games for them
It's not that Nintendo needs new characters it's that they are not using them to their full potential as they should,however they are bring out characters that they rarely used now.
Hopefully they are going to actually bring out the full selection of games to the US and
other places. For every game that makes it over here there are 5 that don't make it over here :/ Though I mainly blame folks that are so jaded.
Oh about a new IP Nintendogs,Tingle(they did...) and several others come to mind.
Don't say the most recent was Pikmin.
http://en.wikipedia.org/wiki/List_of_Nintendo_3DS_games