Naughty Dog wanted Chris Rock to voice Daxter, but he refused the offer. Jason Rubin also wanted George Carlin to voice Samos, but he turned the role down.
Originally there was going to be a third main character that would develop as the game was played in a Tamagotchi style. Instead Naughty Dog concentrated their efforts on two main characters in order to create the exact characters they wanted.
The reason why Jak doesn't talk in this game is because Naughty Dog wanted to enhance the experience and let the player truly feel like they were Jak.
John Kim (Animator of Jak and Daxter) said that Daxter is based on the character Abu from the film Aladdin (1992)
In Ratchet and Clank 2: Going Commando, Ratchet can be see playing Jak and Daxter: The Precursor Legacy in the title screen