According to the official Twitter account of Frontier Works, the production staff of Hetalia: The Beautiful World
will be changed from the previous team.
Hetalia official website
(new character design)
Director: Watanabe Hiroshi
Series Composition: Fudeyasu Kazuyuki
Character Design: Oka Mariko
Production Studio: Studio DEEN not changed
According to Animate.TV, the fifth season will be aired from January 2013.
Sources: Frontier Works