How long will our beloved franchises last?

Seeing all of my (and our) favorite game franchises getting more and more additions at E3 got me thinking. Will these franchises really go on forever, like some would have us believe? Are the Zelda, Kirby, Mario, Donkey Kong, Metroid and Pokemon names getting stretched out too far? 
 
When I saw Skyward Sword demoed at Nintendo's press conference, I wasn't really all that excited. Sure, it was a new Zelda game, and I should be excited, but I really wasn't. It seemed like a step back to me. With all of the games that are "going back to their roots" and getting remade, are we doomed to a continuing cycle of playing the same game, but with better textures?  
 
Donkey Kong is going back to Donkey Kong Country. Mario is doing sports again, and Zelda is the same Zelda we've been playing since N64. 
 
Is it better this way? Am I missing something? Am I the only one who thinks "Kirby's Epic Yarn" isn't a very good name?  
 
Granted, Kirby is different this time around, Other M is being developed by Team Ninja, and there's a Kid Icarus game on the way, but how long will that last?
 
I'm not sure anymore. As gamers, we want to see our favorite characters grow up with us. We don't want them to stop pumping out Zelda or Mario games.  We want to keep stomping Goombas, saving the princess, copying enemies' abilities, getting upgrades, exploring abandoned ships, and catching monsters.
 
I guess if we keep demanding them, they'll keep making them.  
 
Maybe I'm just babbling, but...
 
While I'm on that subject, can I have more The World Ends With You and Phoenix Wright? 
 
(Sorry for all the Nintendo love, it's just the best example from recent events.)