Times change and seeing that current hype for Sony's LittleBigPlanet, I am getting afraid Sackboy might become one of the most popular names for newborns next year: “That's my son Sackboy, doesn't he look just like his daddy?”
Anyway, most likely it is better not to think too much about it. Just get your Sackboy now as long as there are still some available. Or do you really wanna face your girl friend with no Sack (Boy!) on Christmas Eve?