It is most certainly waning in approval. Mostly, I think, do to successful marketing by gun an ammunition manufacturers to the various departments. Firearm and ammunition choices here are as much political (i.e. not based on merit) as they are anything else.
There are several distinct trends in the law enforcement community of late as it goes toward weapons.
Firstly, is the strong trend toward .40 S&W, and to a smaller extent .357 SIG, duty weapons. Usually in a DAO format with such an abysmal trigger-pull it would take an extremely well-trained shooter, which the average officer is not, to use the firearm quickly and accurately.
Next, is a resurgence of single-action 1911s in heavy calibers like .45 ACP for the more elite teams, and some amongst the more competent officers, though they are often not allowed for perceived safety reasons.
Lastly is the move toward lightweight .223 Rem. (5.56x45mm NATO) carbines replacing submachineguns amongst special teams and displacing, or at least complementing, the 12ga shotgun in patrol cars.
