One of the most important things about realizing a voiced character is managing consistency in that voice.
It's the reason that, probably until they each die, Kevin Conroy and David Hayter will be Batman and Solid Snake, respectively. Fans can't imagine the characters any other way.
Unfortunately, fans of Persona 4 may not have this privelage. Teddie, a character appearing in the game, has had his English voice actor changed in the series fighting game spin-off, Persona 4: Arena. This has, of course, caused fans to doubt whether the original cast of Persona 4 will be returning for the game's PlaySation Vita port (recently confirmed for a US launch), Persona 4: Golden.
While Atlus says changes to the cast for Arena don't necessarily indicate changes for Golden, I think it's safe to assume Teddie's original actor is out.