Oh god no, please make them stop!
That's about the only intelligent reaction one could possibly have to the news, reported here in Cinematical, that producer Frank Marshall says a script has been written for JURASSIC PARK IV, which will begin filming next year.
The first JURASSIC PARK was at least based on an interesting novel by Michael Crichton, and a few remnants of his ideas made it onto the screen, along with the lovely dinosaur effects. THE LOST WORLD: JURASSIC PARK abandoned the core of Crichton's sequel and stitched together a sloppy tapestry of leftover bits and pieces -- a process that continued with JURASSIC PARK III. By this point, it's hard to imagine anything else worth doing with the franchise, which has run its course. (Well, actually I have one idea, but they'll never use it. More on that later.)
The problem with the JURASSIC PARK films is that they are based on a situation, and the only thing the sequels can do is contrive a way to get people caught in that situation again, so that we can see more dinosaur footage. "Situation Sequels" of this ilk tend to play out more like remakes, simply rehashing what worked before (albeit often on a larger scale).
The only really interesting sequels are ones that make some progress -- go somewhere we didn't go before. Usually, the way this is accomplished is by taking a continuing character and putting him or her in a new situation, showing how life changes as times passes and new events occur.
This is why you can make endless films about James Bond, Sherlock Holmes, Godzilla, etc. Such films won't necessarily be inspired, and they may even be formulaic, but the formula isn't nearly as rigid as "get some people onto the island full of dinosaurs and have them run for their lives for two hours."
Oh, as for my idea for a new JURASSIC PARK sequel, I outlined it several years ago in a column for Cinefantastique magazine: the film should forget about telling a believable story and opt for a campy MARS ATTACKS approach instead, casting lots of high-profile stars who get eaten in hideously gory ways by the rampaging reptiles. In fact, you could drum up endless publicity with popular Internet polls, in which fans votes for the actors they would most like to see eaten. (I see Adam Sandler near the top of the list, followed closely by Penelope Cruz.)
And if the JURASSIC PARK filmmakers refuse to consider this idea, I at least hope Roger Corman will take it under advisement for CARNOSAUR 6 (or whatever the series has reached), which will no doubt be available on video the week that JURASSIC PARK IV opens in theatres.