In the event that Yoshida does leave, we need someone to follow his disposition toward the game. And not fall into the same mistake ActiBlizzard made of replacing all their roster with uncaring money-makers. To me, Yoshida and all the others should stay (assuming they want to, of course). Because for better or for worse, they're the ones who have made the game what it is, and they aren't the rest of Square Enix.

Regardless, the dev team needs new blood. Not just to replenish the ones they've been losing over time, but also to make room for new ideas and improve on what they already have. Especially to finish their long-term projects. A lot of systems in the game are left unfinished because no one's had time nor patience to pick them back up and polish them.