Jerry Stiller sounds a lot like Don Rickles did in the films. if they want a good match he seems like a good choice. Their replacement for Slinky was very good, and I wouldn't notice a change unless I was really trying to look for it.
But I think Jerry Stiller or Lewis Black could do the best job, in my opinion.
I haven't seen Return of Jafar, but I've watched a couple of clips on Youtube. Dan Castellaneta as Genie felt really weird. He sounded way too much like Homer Simpson. I love Dan Castellaneta in The Simpsons, but I don't think he'd be a good match for Mr Potato Head.
I don't know if they will find a new voice for Potato or kill him off. I mean, take Slink for example. Jim Varney died after Toy Story 2 and Atlantis and got replaced by his friend Blake Clarke. If they can do it to Slinky, they can do it to Potato Head too.
Disney Guardian wrote: Look. i know Eddie Murphy is everyone's top choice to replace Mr. Potato Head, but i think if Eddie Murphy used his unique voice, it would sound much different from Don Rickles' unique voice.
I agree. Love Eddie Murphy as an actor, but the voice would be completely different. In fact, I'd probably just think of Donkey from Shrek everytime I would hear him speak, and it would just take me out of watching the film, because it would be so out of place.
IGN's analysis of the first teaser is stating Alan Tudyk is taking over for the voice, but I'm not finding much anywhere else. Unless they were actually the first ones to report it and the above sites followed, it might've been the reverse where they just took that info from the above links, so still take it with a grain of salt.