A rep from the cable network gave a statement to The Hollywood Reporter on Armando's departure, also naming who will take his place:
We have had conversations with Armando for some time about the challenges of maintaining his family life in London and producing a show in the states. Armando is not replaceable but we are confident that Veep will continue to be produced at the highest levels with new showrunner David Mandel. David has worked with HBO for many years as executive producer, writer and director for Curb Your Enthusiasm."
"Curb" has about the right tone for "Veep," so this could be a mostly painless transition.
Armando's road to "Veep" started with "The Thick Of It," a British TV satire he created to mock the workings of the U.K. government. That led to the hilarious must-watch movie "In the Loop," which Armando directed and features several members of the current "Veep" cast, including Anna Chlumsky. Armando has written and directed several episodes of "Veep" and he has "story by" credits for almost every episode, so it's going to be tough to replace his voice. Season 5 hasn't even been announced yet, but it sounds like HBO has plans to move forward and we just hope the hand-off is more seamless than Selina taking on her new role as POTUS.