I think that the powers that be have done their best to update the Muppets to make them fit in better with today's times...and it just hasn't worked. I say leave the Electric Mayhem alone, find new voices for them, and actually come up with something to do with them. Someone mentioned in another thread the idea of doing a new Muppet movie giving the EM's origins, and I for one would love to see that.
There's no need to update this group. They're cool, odd, quirky characters and being caught in a timewarp should be just part of their appeal. What could they do to modernize them and still let them keep what made them special...let them be the backup singers for Jessica Simpson? I don't think so.