A mainstream topic, but does it mean anything?  There's a guy whose blog I follow (he is/was part of a "skeptics" organization) and he had this to say about it:

We get more indistinct blobs, dots of light, blurry nothings, camera artifacts, and stories of people seeing dots of light. The Pentagon acknowledges – there is no evidence that any of these things are alien phenomena, but also that some of the blobs and lights have not been fully explained. So we are exactly where we have always been – there is no compelling or unambiguous evidence of aliens.

He goes on to reason that it's unlikely Trump is powerless to release any "juicy" files, or that he's trying to cover it up.  In other words, it's just that the government doesn't have evidence of alien life.  

Oh, and I find it interesting that the entire JFK files thing went away, almost as if nothing happened.  All those files were classified for so many decade, only to be released a year or two ago...and nothing.  I never heard that there was anything of note that was in all those hidden files.  Did the U.S. government really want to protect uninteresting files all those years....or did they just to a selective dump while retaining the actually illuminating files about the assassination?