Did you ever Download it on the Playstation Store? Cause I'm pretty sure it's not there anymore, based on what I saw when it comes to the U.S. Store & with the new layout which is confusing to tell if the Beta is still there.
However, the Beta still works. It'll keep decrasing by days as such 0, -1, -2. This is because of the new patch. So yes, you can play the Beta still if you have it Downloaded.
If you can't find it in the PSN Store (if you never Downloaded it), then it's gone.
The beta is still up and playable
Except it's not in the Playstation Store.
Cause the creator of this thread never said if he owned the Beta on the Playstation 3.