It was not too long ago that we saw BBM get updated in BlackBerry Beta Zone, where we saw the introduction to sponsored ads. It looks like an update has been pushed again. There had been some issues that some people had encountered with the previous build and hopefully this update fixes those bugs. There isn't much of a changelog this time, the only thing stated is that the update brings about paid sticker packs.
Once again, this update seems to be in limited beta. Even if you have previously been able to get BBM beta updates, you may not get one this time around. You would normally receive an email telling you of an update. BlackBerry 10 users could also check to see if they see an update via the Beta Zone.