Given that Disney is already developing two more Pirates of the Caribbean sequels, I'm guessing that Jack Sparrow finds the fountain of youth he's looking for in this film. Then Disney will be free to make sequels for all of eternity! Expect Pirates of the Caribbean: The Quest for the Identity-Changing Stone when it comes time to finally replace Depp. In the meantime, check out the preview for On Stranger Tides, which actually looks like about two and a half movies by itself!
I can't imagine how they will cram all of these set pieces, creatures and epic pirate battles into a movie that clocks in at less than four or five hours. The latest trailer somehow has even more action than the last one, a feat which I honestly didn't think was possible.
As far as the plot goes, I think this trailer hints that the film will examine the difficult moral dilemma about whether it's okay to kill a mermaid in order to access the fountain of youth. Since there's footage of a what looks like a mermaid drowning a man, it seems like you could argue either way about the issue. This subject will surely spark lively debates throughout the summer.
Otherwise, if you like action, explosions and quips from Captain Jack Sparrow, it looks like Rob Marshall's got you covered, and then some. Bonus points for the fact that Ian McShane is in this.
Verdict:: I'm not sure I need to see another Pirates of the Caribbean movie, but I don't want to be left out of the debates about killing mermaids... So okay.