Why though? Just so people who should have stopped watching Sesame Street years ago don't have to face the reality of change?
Fact is people get old, they retire, they die. It happens. Now the voice will never sound exactly the same. Sure there are voice actors out there that can probably immitate Caroll spot on, but can they perform the puppet? Can they bring life to a character? Probably not.
No one likes change but you guys have to stop fighting it tooth and nail. Jim Henson isn't coming back, Richard Hunt is not coming back, Caroll Spiney will at some point retire (though god bless him for still staying with it). It just happens. Accept it.