The writing is definitely on the wall for the .357 & .40 since the FBI deemed 9mm better for their uses. Shit always runs down and in the world of law enforcement the FBI is king and was both responsible for the .40 becoming popular and ultimately it's demise. I don't see it ever going away completely as both calibers will always have it's proponents.
That being said, Beretta is not the only maker who has realized the market for .40 is basically no longer valid. CZ does not have ANY .40 SKU's in their lineup AT ALL. SIG only have the P320 in .357 SIG left, I believe... says a lot considering it was their lovechild. It is too bad as IMO, 9mm is fine but leaves a bit to be desired in certain areas of ballistics that both calibers can improve.