I wonder how this affects P-CBS's ability to defend their copyrights, and how it changes the legal picture from the fan production viewpoint---if any. Hopefully, it doesn't change anything from either legal standpoint.
This doesn't have any impact at all on CBS's ability to defend its copyrights whatsoever, because copyrights don't need to be defended to stay fully in force. They are good for 75 years beyond the life of the "author". Period.
Trademarks, on the other hand, must be defended.
And there's where it gets tricky.
See, it's common practice for a company to slap a "TM" on all sorts of things they produce, including things that can't actually be legally trademarked. They do this, because they know that most people will accept the mark at face value, and refrain from using what it pertains to, even though there isn't any real legal barrier to stop them from doing so.
And the truth is that there are many things about Trek that bear the "TM" marking, that couldn't possibly have made it past step one of the Patent Office's trademark approval process, because they simply don't meet any of the criteria.
I think it's safe to say that one of the reasons CBS/Paramount/Whoever doesn't pursue many of the seemingly widespread violations of the Trek trademark, is simply that no legitimate trademarks have actually been violated in many cases, and therefore cannot legally be prosecuted.