It is, so long as you're willing to fiddle around with the PS3's web browser a bit. Go to a Stage6 video you're interested in. For example, we've chosen the PS3's recent Universe of Entertainment ad. Edit the URL in your PS3 browser by pressing START.
URL displayed by browser:
To download this DivX file to your DivX-enabled PS3, you're going to have to edit the video as such: