The rumors continue to mill regarding a new Jurassic Park movie. Stephen Spielberg has officially announced that it’s happening, and the release of the trilogy on Blu-Ray has gotten people talking about it again, but there seems to be virtually no information available beyond that there will be another movie with “Jurassic Park” in the title, and that it will probably also have a “IV” in the title. The other rumors include that Keira Knightley will be in it, that Sam Neil and/or Jeff Goldblum will be back, and that there might be some nonsense regarding genetically-created human-dinosaur-super-monster-soldiers, or that there will be a dinosaur-caused global epidemic or something.
Let’s be honest here: a fourth Jurassic Park movie is a terrible idea. When was the last time you saw a fourth movie in a series that really worked. Before a fourth movie comes out, you have a trilogy. Once a fourth film is tacked onto an original trilogy, you either have a new trilogy (as in the case of The Phantom Menace) or, far more often, you have the beginning of a franchise landslide.

Consider, for a moment, some of the fourth installments out there. First of all, most of the times that a franchise reaches a fourth installment, it doesn’t stop. It becomes a disaster, careening off the rails. Usually, this fate is reserved for trashy horror franchises such as Halloween 4 (which was the fourth of eight), Friday the 13th: The Final Chapter (followed by seven sequels), Saw 4 (which is 4 of 7 and apparently a midquel?), and Nightmare on Elm Street (I didn’t bother looking up how many there were.)

And here are a few that don’t fall into the previously-mentioned category, but are quite possibly the worst of their franchises as well: Scream 4, Alien: Resurrection, (which was followed by several Alien/Predator mash-ups) and Indiana Jones and The Space Aliens or Something.
If I am not mistaken, this has so far been an overwhelmingly compelling argument against Jurassic Park IV. And if you need more convincing, consider the plots of the last three Jurassic Parks. There is no overall continuity between the three films – in fact, no characters that are in all three movies. The films resemble less a trilogy and more a great first film that spawned two mediocre spin-offs. Furthermore, the first two films loosely resemble the two Jurassic Park novels, while the third film is more-or-less a collection of scenes from the two books that didn’t make it into the movies. There is nothing left to pillage from Crichton’s works, unless you want to borrow a couple of the unused moments from Timeline.

The alternate option is, of course, a Bale-Out. It’s been 18 years since the original, and ten years since the third, awful film. Reboot the franchise with Jurassic Park Zero or Jurassic Park: Year One or Jurassic Park: The Island of Dr. Hammond.
What will the plot be, you ask?
Bale is the young, ambitious, cunning Dr. John Hammond, a self-made billionaire who achieved wealth at a young age and now dabbles in various “philanthropic efforts,” which mostly involve genetic engineering and other experiments on the various island he owns. After various half-hearted altruistic efforts to cure disease, Hammond finds himself suffering from nightmares that gradually begin invading his days – visions of terrible lizards, feasting on human flesh and rampaging through cities.

As insomnia begins to take over his nights and these hallucinations consume his waking hours, Hammond realizes that he must bring back the dead creatures that once ruled our world and unleash them onto the planet, as humanity’s time has drawn to an end and he is the one who must finish the human race.
This definitely beats Jurassic Park IV: There’s Still an Island with Dinosaurs on It!
And if you need some final convincing, remember that Jurassic Park already jumped the shark at the end of The Lost World when the T-Rex got loose in San Diego.

I think you’ve struck gold. There was a rumor that in Jurassic Park 4, the dinosaurs would be trained to carry guns. I know that would be terrible . . . but I’m kind of curious how that would look