...I want holodeck

The original series of Star Trek (or Star Trek: TOS has fandom has renamed it) launched on NBC on September 8th 1966, that's 40 years ago this Friday. The show, which ran for a mere three seasons finished its run on June 3rd 1969 and has been in re-runs almost ever since.
It's popularity is such that 40 years after it started CBS are currently working on re-mastered versions of some of the original episodes complete with new CGI for release into syndication again.
But Star Trek is a lot more than just a science fiction show that has stood the test of time. It's more even than the start of a popular franchise. Star Trek represents the entrance of science fiction into popular culture.
Star Trek was far from the first sci-fi show on tv and if you trace these things back, there were many pulp serials in the cinema along the lines of Flash Gordon which had some or many sci-fi elements. But Star Trek was different. For one thing it treated the source material with more reverence. I can't claim that all the science fiction in Star Trek was good (some of it was plain bad), but some of it was very good and much of it was based on established science fiction concepts.
The eventual success of Star Trek paved the way for a television landscape where science fiction shows routinely turn up on network tv.
Memories of Star Trek
Star Trek has never ranked in my personal top 5 of sci-fi shows. Perhaps that's because I'm from the UK and our own sci-fi shows usually got better tv slots. However I do have some vivid memories from my childhood of watching episodes. Scenes from The Doomsday Machine episode are still burned into my mind 20+ years later.
I can claim to have watched episodes of every series of Star Trek, including the entire runs of The Original Series and The Next Generation. It wasn't until the later shows that my interest in the series really diminished. Perhaps it was the lack of originality, maybe it was just too much too close together, but by the time that Star Trek: Voyager and Star Trek: Enterprise arrived on the scene, I rarely tuned in.
The Future of Star Trek
Now, as the 40th anniversary of Star Trek arrives, there is no Star Trek on tv for the first time in over a decade and no sign of one in the near future. But this certainly isn't the end for Star Trek. Rumors continue to swirl over the proposed Star Trek XI movie which currently has J. J. Abrams (Lost) attached as a producer.
Will this movie trigger a Star Trek revival? Probably not, the movie is heavily rumored to be a prequel of some sort to the original Star Trek series. While this has a lot of potential for drawing in the more casual Trek audience, it doesn't leave many opportunities to move the franchise in a new direction.
For the moment it seems that Trek has written itself into a corner and until someone can come up with a new vision for the franchise it is probably best that it stays off tv. It won't be gone for ever of that I'm sure. Star Trek has lasted 40 years, it's not likely to die now.